STATISTICAL ANALYSIS OF SPECTROPHOTOMETRIC DETERMINATIONS OF BORON; Estudo Estatistico de Determinacoes Espectrofotometricas de Boro

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

Lima, F.W.; Pagano, C.; Schneiderman, B.

1959-07-01

Boron can be determined quantitatively by absorption spectrophotometry of solutions of the red compound formed by the reaction of boric acid with curcumin. This reaction is affected by various factors, some of which can be detected easily in the data interpretation. Others, however, provide more difficulty. The application of modern statistical method to the study of the influence of these factors on the quantitative determination of boron is presented. These methods provide objective ways of establishing significant effects of the factors involved. (auth)

Analysis of the sleep quality of elderly people using biomedical signals.

PubMed

Moreno-Alsasua, L; Garcia-Zapirain, B; Mendez-Zorrilla, A

2015-01-01

This paper presents a technical solution that analyses sleep signals captured by biomedical sensors to find possible disorders during rest. Specifically, the method evaluates electrooculogram (EOG) signals, skin conductance (GSR), air flow (AS), and body temperature. Next, a quantitative sleep quality analysis determines significant changes in the biological signals, and any similarities between them in a given time period. Filtering techniques such as the Fourier transform method and IIR filters process the signal and identify significant variations. Once these changes have been identified, all significant data is compared and a quantitative and statistical analysis is carried out to determine the level of a person's rest. To evaluate the correlation and significant differences, a statistical analysis has been calculated showing correlation between EOG and AS signals (p=0,005), EOG, and GSR signals (p=0,037) and, finally, the EOG and Body temperature (p=0,04). Doctors could use this information to monitor changes within a patient.

Quantitative analysis of γ-oryzanol content in cold pressed rice bran oil by TLC-image analysis method.

PubMed

Sakunpak, Apirak; Suksaeree, Jirapornchai; Monton, Chaowalit; Pathompak, Pathamaporn; Kraisintu, Krisana

2014-02-01

To develop and validate an image analysis method for quantitative analysis of γ-oryzanol in cold pressed rice bran oil. TLC-densitometric and TLC-image analysis methods were developed, validated, and used for quantitative analysis of γ-oryzanol in cold pressed rice bran oil. The results obtained by these two different quantification methods were compared by paired t-test. Both assays provided good linearity, accuracy, reproducibility and selectivity for determination of γ-oryzanol. The TLC-densitometric and TLC-image analysis methods provided a similar reproducibility, accuracy and selectivity for the quantitative determination of γ-oryzanol in cold pressed rice bran oil. A statistical comparison of the quantitative determinations of γ-oryzanol in samples did not show any statistically significant difference between TLC-densitometric and TLC-image analysis methods. As both methods were found to be equal, they therefore can be used for the determination of γ-oryzanol in cold pressed rice bran oil.

Quantitative analysis of γ-oryzanol content in cold pressed rice bran oil by TLC-image analysis method

PubMed Central

Sakunpak, Apirak; Suksaeree, Jirapornchai; Monton, Chaowalit; Pathompak, Pathamaporn; Kraisintu, Krisana

2014-01-01

Objective To develop and validate an image analysis method for quantitative analysis of γ-oryzanol in cold pressed rice bran oil. Methods TLC-densitometric and TLC-image analysis methods were developed, validated, and used for quantitative analysis of γ-oryzanol in cold pressed rice bran oil. The results obtained by these two different quantification methods were compared by paired t-test. Results Both assays provided good linearity, accuracy, reproducibility and selectivity for determination of γ-oryzanol. Conclusions The TLC-densitometric and TLC-image analysis methods provided a similar reproducibility, accuracy and selectivity for the quantitative determination of γ-oryzanol in cold pressed rice bran oil. A statistical comparison of the quantitative determinations of γ-oryzanol in samples did not show any statistically significant difference between TLC-densitometric and TLC-image analysis methods. As both methods were found to be equal, they therefore can be used for the determination of γ-oryzanol in cold pressed rice bran oil. PMID:25182282

A Quantitative Features Analysis of Recommended No- and Low-Cost Preschool E-Books

ERIC Educational Resources Information Center

Parette, Howard P.; Blum, Craig; Luthin, Katie

2015-01-01

In recent years, recommended e-books have drawn increasing attention from early childhood education professionals. This study applied a quantitative descriptive features analysis of cost (n = 70) and no-cost (n = 60) e-books recommended by the Texas Computer Education Association. While t tests revealed no statistically significant differences…

Inclusion and Student Learning: A Quantitative Comparison of Special and General Education Student Performance Using Team and Solo-Teaching

ERIC Educational Resources Information Center

Jamison, Joseph A.

2013-01-01

This quantitative study sought to determine whether there were significant statistical differences between the performance scores of special education and general education students' scores when in team or solo-teaching environments as may occur in inclusively taught classrooms. The investigated problem occurs because despite education's stated…

Teaching Biology through Statistics: Application of Statistical Methods in Genetics and Zoology Courses

ERIC Educational Resources Information Center

Colon-Berlingeri, Migdalisel; Burrowes, Patricia A.

2011-01-01

Incorporation of mathematics into biology curricula is critical to underscore for undergraduate students the relevance of mathematics to most fields of biology and the usefulness of developing quantitative process skills demanded in modern biology. At our institution, we have made significant changes to better integrate mathematics into the…

Condenser: a statistical aggregation tool for multi-sample quantitative proteomic data from Matrix Science Mascot Distiller™.

PubMed

Knudsen, Anders Dahl; Bennike, Tue; Kjeldal, Henrik; Birkelund, Svend; Otzen, Daniel Erik; Stensballe, Allan

2014-05-30

We describe Condenser, a freely available, comprehensive open-source tool for merging multidimensional quantitative proteomics data from the Matrix Science Mascot Distiller Quantitation Toolbox into a common format ready for subsequent bioinformatic analysis. A number of different relative quantitation technologies, such as metabolic (15)N and amino acid stable isotope incorporation, label-free and chemical-label quantitation are supported. The program features multiple options for curative filtering of the quantified peptides, allowing the user to choose data quality thresholds appropriate for the current dataset, and ensure the quality of the calculated relative protein abundances. Condenser also features optional global normalization, peptide outlier removal, multiple testing and calculation of t-test statistics for highlighting and evaluating proteins with significantly altered relative protein abundances. Condenser provides an attractive addition to the gold-standard quantitative workflow of Mascot Distiller, allowing easy handling of larger multi-dimensional experiments. Source code, binaries, test data set and documentation are available at http://condenser.googlecode.com/. Copyright © 2014 Elsevier B.V. All rights reserved.

LC–MS/MS Quantitation of Esophagus Disease Blood Serum Glycoproteins by Enrichment with Hydrazide Chemistry and Lectin Affinity Chromatography

PubMed Central

2015-01-01

Changes in glycosylation have been shown to have a profound correlation with development/malignancy in many cancer types. Currently, two major enrichment techniques have been widely applied in glycoproteomics, namely, lectin affinity chromatography (LAC)-based and hydrazide chemistry (HC)-based enrichments. Here we report the LC–MS/MS quantitative analyses of human blood serum glycoproteins and glycopeptides associated with esophageal diseases by LAC- and HC-based enrichment. The separate and complementary qualitative and quantitative data analyses of protein glycosylation were performed using both enrichment techniques. Chemometric and statistical evaluations, PCA plots, or ANOVA test, respectively, were employed to determine and confirm candidate cancer-associated glycoprotein/glycopeptide biomarkers. Out of 139, 59 common glycoproteins (42% overlap) were observed in both enrichment techniques. This overlap is very similar to previously published studies. The quantitation and evaluation of significantly changed glycoproteins/glycopeptides are complementary between LAC and HC enrichments. LC–ESI–MS/MS analyses indicated that 7 glycoproteins enriched by LAC and 11 glycoproteins enriched by HC showed significantly different abundances between disease-free and disease cohorts. Multiple reaction monitoring quantitation resulted in 13 glycopeptides by LAC enrichment and 10 glycosylation sites by HC enrichment to be statistically different among disease cohorts. PMID:25134008

Concerns and professional development needs of science faculty at Taibah University in adopting blended learning

NASA Astrophysics Data System (ADS)

Al-Sarrani, Nauaf

The purpose of this study was to obtain Science faculty concerns and professional development needs to adopt blended learning in their teaching at Taibah University. To answer these two research questions the survey instrument was designed to collect quantitative and qualitative data from close-ended and open-ended questions. The participants' general characteristics were first presented, then the quantitative measures were presented as the results of the null hypotheses. The data analysis for research question one revealed a statistically significant difference in the participants' concerns in adopting BL by their gender sig = .0015. The significances were found in stages one (sig = .000) and stage five (sig = .006) for female faculty. Therefore, null hypothesis 1.1 was rejected (There are no statistically significant differences between science faculty's gender and their concerns in adopting BL). The data analysis indicated also that there were no relationships between science faculty's age, academic rank, nationality, country of graduation and years of teaching experience and their concerns in adopting BL in their teaching, so the null hypotheses 1.2-7 were accepted (There are no statistically significant differences between Science faculty's age and their concerns in adopting BL, there are no statistically significant differences between Science faculty's academic rank and their concerns in adopting BL, there are no statistically significant differences between Science faculty's nationality and their concerns in adopting BL, there are no statistically significant differences between Science faculty's content area and their concerns in adopting BL, there are no statistically significant differences between Science faculty's country of graduation and their concerns in adopting BL and there are no statistically significant differences between Science faculty's years of teaching experience and their concerns in adopting BL). The data analyses for research question two revealed that there was a statistically significant difference between science faculty's use of technology in teaching by department and their attitudes towards technology integration in the Science curriculum. Lambda MANOVA test result was sig =.019 at the alpha = .05 level. Follow up ANOVA result indicated that Chemistry department was significant in the use of computer-based technology (sig =.049) and instructional technology use (sig =.041). Therefore, null hypothesis 2.1 was rejected (There are no statistically significant differences between science faculty's attitudes towards technology integration in the Science curriculum and faculty's use of technology in teaching by department). The data also revealed that there was no statistically significant difference (p<.05) between science faculty's use of technology in teaching by department and their instructional technology use on pedagogy. Therefore, null hypothesis 2.2 was accepted (There are no statistically significant differences between science faculty's perceptions of the effects of faculty IT use on pedagogy and faculty's use of technology in teaching by department). The data also revealed that there was a statistically significant difference between science faculty's use of technology in teaching by department and their professional development needs in adopting BL. Lambda MANOVA test result was .007 at the alpha = .05 level. The follow up ANOVA results showed that the value of significance of Science faculty's professional development needs for adopting BL was smaller than .05 in the Chemistry department with sig =.001 in instructional technology use. Therefore, null hypothesis 2.3 was rejected (There are no statistically significant differences between Science faculty's perceptions of technology professional development needs and faculty's use of technology in teaching by department). Qualitative measures included analyzing data based on answers to three open-ended questions, numbers thirty-six, seventy-four, and seventy-five. These three questions were on blended learning concerns comments (question 36, which had 10 units), professional development activities, support, or incentive requested (question 74, which had 28 units), and the most important professional development activities, support, or incentive (question 75, which had 37 units). These questions yielded 75 units, 23 categories and 8 themes that triangulated with the quantitative data. These 8 themes were then combined to obtain overall themes for all qualitative questions in the study. The two most important themes were "Professional development" with three categories; Professional development through workshops (10 units), Workshops (10 units), Professional development (5 units) and the second overall theme was "Technical support" with two categories: Internet connectivity (4 units), and Technical support (4 units). Finally, based on quantitative and qualitative data, the summary, conclusions, and recommendations for Taibah University regarding faculty adoption of BL in teaching were presented. The recommendations for future studies focused on Science faculty Level of Use and technology use in Saudi universities.

Quantitative characterization of nonstructural carbohydrates of mezcal Agave (Agave salmiana Otto ex Salm-Dick).

PubMed

Michel-Cuello, Christian; Juárez-Flores, Bertha Irene; Aguirre-Rivera, Juan Rogelio; Pinos-Rodríguez, Juan Manuel

2008-07-23

Fructans are the reserve carbohydrates in Agave spp. plants. In mezcal factories, fructans undergoes thermal hydrolysis to release fructose and glucose, which are the basis to produce this spirit. Carbohydrate content determines the yield of the final product, which depends on plant organ, ripeness stage, and thermal hydrolysis. Thus, a qualitative and quantitative characterization of nonstructural carbohydrates was conducted in raw and hydrolyzed juices extracted from Agave salmiana stems and leaves under three ripeness stages. By high-performance liquid chromatography (HPLC), fructose, glucose, sucrose, xylose, and maltose were identified in agave juice. Only the plant fraction with hydrolysis interaction was found to be significant in the glucose concentration plant. Interactions of the fraction with hydrolysis and ripeness with hydrolysis were statistically significant in fructose concentration. Fructose concentration rose considerably with hydrolysis, but only in juice extracted from ripe agave stems (early mature and castrated). This increase was statistically significant only with acid hydrolysis.

Incorporating an Interactive Statistics Workshop into an Introductory Biology Course-Based Undergraduate Research Experience (CURE) Enhances Students’ Statistical Reasoning and Quantitative Literacy Skills †

PubMed Central

Olimpo, Jeffrey T.; Pevey, Ryan S.; McCabe, Thomas M.

2018-01-01

Course-based undergraduate research experiences (CUREs) provide an avenue for student participation in authentic scientific opportunities. Within the context of such coursework, students are often expected to collect, analyze, and evaluate data obtained from their own investigations. Yet, limited research has been conducted that examines mechanisms for supporting students in these endeavors. In this article, we discuss the development and evaluation of an interactive statistics workshop that was expressly designed to provide students with an open platform for graduate teaching assistant (GTA)-mentored data processing, statistical testing, and synthesis of their own research findings. Mixed methods analyses of pre/post-intervention survey data indicated a statistically significant increase in students’ reasoning and quantitative literacy abilities in the domain, as well as enhancement of student self-reported confidence in and knowledge of the application of various statistical metrics to real-world contexts. Collectively, these data reify an important role for scaffolded instruction in statistics in preparing emergent scientists to be data-savvy researchers in a globally expansive STEM workforce. PMID:29904549

Incorporating an Interactive Statistics Workshop into an Introductory Biology Course-Based Undergraduate Research Experience (CURE) Enhances Students' Statistical Reasoning and Quantitative Literacy Skills.

PubMed

Olimpo, Jeffrey T; Pevey, Ryan S; McCabe, Thomas M

2018-01-01

Course-based undergraduate research experiences (CUREs) provide an avenue for student participation in authentic scientific opportunities. Within the context of such coursework, students are often expected to collect, analyze, and evaluate data obtained from their own investigations. Yet, limited research has been conducted that examines mechanisms for supporting students in these endeavors. In this article, we discuss the development and evaluation of an interactive statistics workshop that was expressly designed to provide students with an open platform for graduate teaching assistant (GTA)-mentored data processing, statistical testing, and synthesis of their own research findings. Mixed methods analyses of pre/post-intervention survey data indicated a statistically significant increase in students' reasoning and quantitative literacy abilities in the domain, as well as enhancement of student self-reported confidence in and knowledge of the application of various statistical metrics to real-world contexts. Collectively, these data reify an important role for scaffolded instruction in statistics in preparing emergent scientists to be data-savvy researchers in a globally expansive STEM workforce.

QR-STEM: Energy and Environment as a Context for Improving QR and STEM Understandings of 6-12 Grade Teachers II. The Quantitative Reasoning

NASA Astrophysics Data System (ADS)

Mayes, R.; Lyford, M. E.; Myers, J. D.

2009-12-01

The Quantitative Reasoning in STEM (QR STEM) project is a state level Mathematics and Science Partnership Project (MSP) with a focus on the mathematics and statistics that underlies the understanding of complex global scientific issues. This session is a companion session to the QR STEM: The Science presentation. The focus of this session is the quantitative reasoning aspects of the project. As students move from understandings that range from local to global in perspective on issues of energy and environment, there is a significant increase in the need for mathematical and statistical conceptual understanding. These understandings must be accessible to the students within the scientific context, requiring the special understandings that are endemic within quantitative reasoning. The QR STEM project brings together interdisciplinary teams of higher education faculty and middle/high school teachers to explore complex problems in energy and environment. The disciplines include life sciences, physics, chemistry, earth science, statistics, and mathematics. These interdisciplinary teams develop open ended performance tasks to implement in the classroom, based on scientific concepts that underpin energy and environment. Quantitative reasoning is broken down into three components: Quantitative Literacy, Quantitative Interpretation, and Quantitative Modeling. Quantitative Literacy is composed of arithmetic concepts such as proportional reasoning, numeracy, and descriptive statistics. Quantitative Interpretation includes algebraic and geometric concepts that underlie the ability to interpret a model of natural phenomena which is provided for the student. This model may be a table, graph, or equation from which the student is to make predictions or identify trends, or from which they would use statistics to explore correlations or patterns in data. Quantitative modeling is the ability to develop the model from data, including the ability to test hypothesis using statistical procedures. We use the term model very broadly, so it includes visual models such as box models, as well as best fit equation models and hypothesis testing. One of the powerful outcomes of the project is the conversation which takes place between science teachers and mathematics teachers. First they realize that though they are teaching concepts that cross their disciplines, the barrier of scientific language within their subjects restricts students from applying the concepts across subjects. Second the mathematics teachers discover the context of science as a means of providing real world situations that engage students in the utility of mathematics as a tool for solving problems. Third the science teachers discover the barrier to understanding science that is presented by poor quantitative reasoning ability. Finally the students are engaged in exploring energy and environment in a manner which exposes the importance of seeing a problem from multiple interdisciplinary perspectives. The outcome is a democratic citizen capable of making informed decisions, and perhaps a future scientist.

[Applications of mathematical statistics methods on compatibility researches of traditional Chinese medicines formulae].

PubMed

Mai, Lan-Yin; Li, Yi-Xuan; Chen, Yong; Xie, Zhen; Li, Jie; Zhong, Ming-Yu

2014-05-01

The compatibility of traditional Chinese medicines (TCMs) formulae containing enormous information, is a complex component system. Applications of mathematical statistics methods on the compatibility researches of traditional Chinese medicines formulae have great significance for promoting the modernization of traditional Chinese medicines and improving clinical efficacies and optimizations of formulae. As a tool for quantitative analysis, data inference and exploring inherent rules of substances, the mathematical statistics method can be used to reveal the working mechanisms of the compatibility of traditional Chinese medicines formulae in qualitatively and quantitatively. By reviewing studies based on the applications of mathematical statistics methods, this paper were summarized from perspective of dosages optimization, efficacies and changes of chemical components as well as the rules of incompatibility and contraindication of formulae, will provide the references for further studying and revealing the working mechanisms and the connotations of traditional Chinese medicines.

A quantitative analysis of factors influencing the professional longevity of high school science teachers in Florida

NASA Astrophysics Data System (ADS)

Ridgley, James Alexander, Jr.

This dissertation is an exploratory quantitative analysis of various independent variables to determine their effect on the professional longevity (years of service) of high school science teachers in the state of Florida for the academic years 2011-2012 to 2013-2014. Data are collected from the Florida Department of Education, National Center for Education Statistics, and the National Assessment of Educational Progress databases. The following research hypotheses are examined: H1 - There are statistically significant differences in Level 1 (teacher variables) that influence the professional longevity of a high school science teacher in Florida. H2 - There are statistically significant differences in Level 2 (school variables) that influence the professional longevity of a high school science teacher in Florida. H3 - There are statistically significant differences in Level 3 (district variables) that influence the professional longevity of a high school science teacher in Florida. H4 - When tested in a hierarchical multiple regression, there are statistically significant differences in Level 1, Level 2, or Level 3 that influence the professional longevity of a high school science teacher in Florida. The professional longevity of a Floridian high school science teacher is the dependent variable. The independent variables are: (Level 1) a teacher's sex, age, ethnicity, earned degree, salary, number of schools taught in, migration count, and various years of service in different areas of education; (Level 2) a school's geographic location, residential population density, average class size, charter status, and SES; and (Level 3) a school district's average SES and average spending per pupil. Statistical analyses of exploratory MLRs and a HMR are used to support the research hypotheses. The final results of the HMR analysis show a teacher's age, salary, earned degree (unknown, associate, and doctorate), and ethnicity (Hispanic and Native Hawaiian/Pacific Islander); a school's charter status; and a school district's average SES are all significant predictors of a Florida high school science teacher's professional longevity. Although statistically significant in the initial exploratory MLR analyses, a teacher's ethnicity (Asian and Black), a school's geographic location (city and rural), and a school's SES are not statistically significant in the final HMR model.

Is math anxiety in the secondary classroom limiting physics mastery? A study of math anxiety and physics performance

NASA Astrophysics Data System (ADS)

Mercer, Gary J.

This quantitative study examined the relationship between secondary students with math anxiety and physics performance in an inquiry-based constructivist classroom. The Revised Math Anxiety Rating Scale was used to evaluate math anxiety levels. The results were then compared to the performance on a physics standardized final examination. A simple correlation was performed, followed by a multivariate regression analysis to examine effects based on gender and prior math background. The correlation showed statistical significance between math anxiety and physics performance. The regression analysis showed statistical significance for math anxiety, physics performance, and prior math background, but did not show statistical significance for math anxiety, physics performance, and gender.

78 FR 70059 - Agency Information Collection Activities: Proposed Collection; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-22

... (as opposed to quantitative statistical methods). In consultation with research experts, we have... qualitative interviews (as opposed to quantitative statistical methods). In consultation with research experts... utilization of qualitative interviews (as opposed to quantitative statistical methods). In consultation with...

A statistical approach to selecting and confirming validation targets in -omics experiments

PubMed Central

2012-01-01

Background Genomic technologies are, by their very nature, designed for hypothesis generation. In some cases, the hypotheses that are generated require that genome scientists confirm findings about specific genes or proteins. But one major advantage of high-throughput technology is that global genetic, genomic, transcriptomic, and proteomic behaviors can be observed. Manual confirmation of every statistically significant genomic result is prohibitively expensive. This has led researchers in genomics to adopt the strategy of confirming only a handful of the most statistically significant results, a small subset chosen for biological interest, or a small random subset. But there is no standard approach for selecting and quantitatively evaluating validation targets. Results Here we present a new statistical method and approach for statistically validating lists of significant results based on confirming only a small random sample. We apply our statistical method to show that the usual practice of confirming only the most statistically significant results does not statistically validate result lists. We analyze an extensively validated RNA-sequencing experiment to show that confirming a random subset can statistically validate entire lists of significant results. Finally, we analyze multiple publicly available microarray experiments to show that statistically validating random samples can both (i) provide evidence to confirm long gene lists and (ii) save thousands of dollars and hundreds of hours of labor over manual validation of each significant result. Conclusions For high-throughput -omics studies, statistical validation is a cost-effective and statistically valid approach to confirming lists of significant results. PMID:22738145

Assessment of renal perfusion with contrast-enhanced ultrasound: Preliminary results in early diabetic nephropathies.

PubMed

Dong, Yi; Wang, Wen-Ping; Lin, Pan; Fan, Peili; Mao, Feng

2016-01-01

We performed a prospective study to evaluate the value of contrast-enhanced ultrasound (CEUS) in quantitative evaluation of renal cortex perfusion in patients suspected of early diabetic nephropathies (DN), with the estimated GFR (MDRD equation) as the gold standard. The study protocol was approved by the hospital review board; each patient gave written informed consent. Our study included 46 cases (21 males and 25 females, mean age 55.6 ± 4.14 years) of clinical confirmed early DN patients. After intravenous bolus injection of 1 ml sulfur hexafluoride microbubbles of ultrasound contrast agent, real time CEUS of renal cortex was performed successively using a 2-5 MHz convex probe. Time-intensity curves (TICs) and quantitative indexes were created with Qlab software. Receiver operating characteristic (ROC) curves were used to predict the diagnostic criteria of CEUS quantitative indexes, and their diagnostic efficiencies were compared with resistance index (RI) and peak systolic velocity (PSV) of renal segmental arteries by chi square test. Our control group included forty-five healthy volunteers. Difference was considered statistically significant with P <  0.05. Changes of area under curve (AUC), derived peak intensity (DPI) were statistically significant (P <  0.05). DPI less than 12 and AUC greater than 1400 had high utility in DN, with 71.7% and 67.3% sensitivity, 77.8% and 80.0% specificity. These results were significantly better than those obtained with RI and PSV which had no significant difference in early stage of DN (P > 0.05). CEUS might be helpful to improve early diagnosis of DN by quantitative analyses. AUC and DPI might be valuable quantitative indexes.

Current Status of Biomedical Book Reviewing: Part I. Key Biomedical Reviewing Journals with Quantitative Significance

PubMed Central

Chen, Ching-Chih; Wright, Arthuree M.

1974-01-01

This is the first part of a comprehensive, quantitative study of biomedical book reviewing. The data base of the total project was built from statistics taken from all 1970 issues of biomedical journals held in the Science Library of the Massachusetts Institute of Technology. Of 285 so-called “life sciences” journals held by that library, fifty-four English journals (excluding Science and Nature) were found to contain bona fide book reviews (as contrasted with mere author-title lists) and were therefore selected for close study. The statistical results reveal that there were 3,347 reviews of 2,067 biomedical books in these fifty-four selected journals in 1970. Part I of the study identifies key biomedical reviewing journals of quantitative significance. The top ten journals, British Medical Journal, Lancet, Annals of Internal Medicine, Journal of the American Medical Association, Archives of Internal Medicine, New England Journal of Medicine, Quarterly Review of Biology, Bioscience, Canadian Medical Association Journal,* and American Journal of the Medical Sciences, accounted for 63.03% of the total number of reviews in 1970. PMID:4826479

Current status of biomedical book reviewing. I. Key biomedical reviewing journals with quantitative significance.

PubMed

Chen, C C; Wright, A M

1974-04-01

This is the first part of a comprehensive, quantitative study of biomedical book reviewing. The data base of the total project was built from statistics taken from all 1970 issues of biomedical journals held in the Science Library of the Massachusetts Institute of Technology. Of 285 so-called "life sciences" journals held by that library, fifty-four English journals (excluding Science and Nature) were found to contain bona fide book reviews (as contrasted with mere author-title lists) and were therefore selected for close study. The statistical results reveal that there were 3,347 reviews of 2,067 biomedical books in these fifty-four selected journals in 1970. Part I of the study identifies key biomedical reviewing journals of quantitative significance. The top ten journals, British Medical Journal, Lancet, Annals of Internal Medicine, Journal of the American Medical Association, Archives of Internal Medicine, New England Journal of Medicine, Quarterly Review of Biology, Bioscience, Canadian Medical Association Journal,(*) and American Journal of the Medical Sciences, accounted for 63.03% of the total number of reviews in 1970.

Science Journals in the Garden: Developing the Skill of Observation in Elementary Age Students

NASA Astrophysics Data System (ADS)

Kelly, Karinsa Michelle

The ability to make and record scientific observations is critical in order for students to engage in successful inquiry, and provides a sturdy foundation for children to develop higher order cognitive processes. Nevertheless, observation is taken for granted in the elementary classroom. This study explores how linking school garden experience with the use of science journals can support this skill. Students participated in a month-long unit in which they practiced their observation skills in the garden and recorded those observations in a science journal. Students' observational skills were assessed using pre- and post-assessments, student journals, and student interviews using three criteria: Accuracy, Detail, and Quantitative Data. Statistically significant improvements were found in the categories of Detail and Quantitative Data. Scores did improve in the category of Accuracy, but it was not found to be a statistically significant improvement.

Quantitative Ultrasound for Measuring Obstructive Severity in Children with Hydronephrosis.

PubMed

Cerrolaza, Juan J; Peters, Craig A; Martin, Aaron D; Myers, Emmarie; Safdar, Nabile; Linguraru, Marius George

2016-04-01

We define sonographic biomarkers for hydronephrotic renal units that can predict the necessity of diuretic nuclear renography. We selected a cohort of 50 consecutive patients with hydronephrosis of varying severity in whom 2-dimensional sonography and diuretic mercaptoacetyltriglycine renography had been performed. A total of 131 morphological parameters were computed using quantitative image analysis algorithms. Machine learning techniques were then applied to identify ultrasound based safety thresholds that agreed with the t½ for washout. A best fit model was then derived for each threshold level of t½ that would be clinically relevant at 20, 30 and 40 minutes. Receiver operating characteristic curve analysis was performed. Sensitivity, specificity and area under the receiver operating characteristic curve were determined. Improvement obtained by the quantitative imaging method compared to the Society for Fetal Urology grading system and the hydronephrosis index was statistically verified. For the 3 thresholds considered and at 100% sensitivity the specificities of the quantitative imaging method were 94%, 70% and 74%, respectively. Corresponding area under the receiver operating characteristic curve values were 0.98, 0.94 and 0.94, respectively. Improvement obtained by the quantitative imaging method over the Society for Fetal Urology grade and hydronephrosis index was statistically significant (p <0.05 in all cases). Quantitative imaging analysis of renal sonograms in children with hydronephrosis can identify thresholds of clinically significant washout times with 100% sensitivity to decrease the number of diuretic renograms in up to 62% of children. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Multivariate analysis, mass balance techniques, and statistical tests as tools in igneous petrology: application to the Sierra de las Cruces volcanic range (Mexican Volcanic Belt).

PubMed

Velasco-Tapia, Fernando

2014-01-01

Magmatic processes have usually been identified and evaluated using qualitative or semiquantitative geochemical or isotopic tools based on a restricted number of variables. However, a more complete and quantitative view could be reached applying multivariate analysis, mass balance techniques, and statistical tests. As an example, in this work a statistical and quantitative scheme is applied to analyze the geochemical features for the Sierra de las Cruces (SC) volcanic range (Mexican Volcanic Belt). In this locality, the volcanic activity (3.7 to 0.5 Ma) was dominantly dacitic, but the presence of spheroidal andesitic enclaves and/or diverse disequilibrium features in majority of lavas confirms the operation of magma mixing/mingling. New discriminant-function-based multidimensional diagrams were used to discriminate tectonic setting. Statistical tests of discordancy and significance were applied to evaluate the influence of the subducting Cocos plate, which seems to be rather negligible for the SC magmas in relation to several major and trace elements. A cluster analysis following Ward's linkage rule was carried out to classify the SC volcanic rocks geochemical groups. Finally, two mass-balance schemes were applied for the quantitative evaluation of the proportion of the end-member components (dacitic and andesitic magmas) in the comingled lavas (binary mixtures).

A quantitative study of factors influencing quality of life in rural Mexican women diagnosed with HIV.

PubMed

Holtz, Carol; Sowell, Richard; VanBrackle, Lewis; Velasquez, Gabriela; Hernandez-Alonso, Virginia

2014-01-01

This quantitative study explored the level of Quality of Life (QoL) in indigenous Mexican women and identified psychosocial factors that significantly influenced their QoL, using face-to-face interviews with 101 women accessing care in an HIV clinic in Oaxaca, Mexico. Variables included demographic characteristics, levels of depression, coping style, family functioning, HIV-related beliefs, and QoL. Descriptive statistics were used to analyze participant characteristics, and women's scores on data collection instruments. Pearson's R correlational statistics were used to determine the level of significance between study variables. Multiple regression analysis examined all variables that were significantly related to QoL. Pearson's correlational analysis of relationships between Spirituality, Educating Self about HIV, Family Functioning, Emotional Support, Physical Care, and Staying Positive demonstrated positive correlation to QoL. Stigma, depression, and avoidance coping were significantly and negatively associated with QoL. The final regression model indicated that depression and avoidance coping were the best predictor variables for QoL. Copyright © 2014 Association of Nurses in AIDS Care. Published by Elsevier Inc. All rights reserved.

Clinical significance of quantitative analysis of facial nerve enhancement on MRI in Bell's palsy.

PubMed

Song, Mee Hyun; Kim, Jinna; Jeon, Ju Hyun; Cho, Chang Il; Yoo, Eun Hye; Lee, Won-Sang; Lee, Ho-Ki

2008-11-01

Quantitative analysis of the facial nerve on the lesion side as well as the normal side, which allowed for more accurate measurement of facial nerve enhancement in patients with facial palsy, showed statistically significant correlation with the initial severity of facial nerve inflammation, although little prognostic significance was shown. This study investigated the clinical significance of quantitative measurement of facial nerve enhancement in patients with Bell's palsy by analyzing the enhancement pattern and correlating MRI findings with initial severity of facial palsy and clinical outcome. Facial nerve enhancement was measured quantitatively by using the region of interest on pre- and postcontrast T1-weighted images in 44 patients diagnosed with Bell's palsy. The signal intensity increase on the lesion side was first compared with that of the contralateral side and then correlated with the initial degree of facial palsy and prognosis. The lesion side showed significantly higher signal intensity increase compared with the normal side in all of the segments except for the mastoid segment. Signal intensity increase at the internal auditory canal and labyrinthine segments showed correlation with the initial degree of facial palsy but no significant difference was found between different prognostic groups.

Teaching statistics in biology: using inquiry-based learning to strengthen understanding of statistical analysis in biology laboratory courses.

PubMed

Metz, Anneke M

2008-01-01

There is an increasing need for students in the biological sciences to build a strong foundation in quantitative approaches to data analyses. Although most science, engineering, and math field majors are required to take at least one statistics course, statistical analysis is poorly integrated into undergraduate biology course work, particularly at the lower-division level. Elements of statistics were incorporated into an introductory biology course, including a review of statistics concepts and opportunity for students to perform statistical analysis in a biological context. Learning gains were measured with an 11-item statistics learning survey instrument developed for the course. Students showed a statistically significant 25% (p < 0.005) increase in statistics knowledge after completing introductory biology. Students improved their scores on the survey after completing introductory biology, even if they had previously completed an introductory statistics course (9%, improvement p < 0.005). Students retested 1 yr after completing introductory biology showed no loss of their statistics knowledge as measured by this instrument, suggesting that the use of statistics in biology course work may aid long-term retention of statistics knowledge. No statistically significant differences in learning were detected between male and female students in the study.

Genetic interactions contribute less than additive effects to quantitative trait variation in yeast

PubMed Central

Bloom, Joshua S.; Kotenko, Iulia; Sadhu, Meru J.; Treusch, Sebastian; Albert, Frank W.; Kruglyak, Leonid

2015-01-01

Genetic mapping studies of quantitative traits typically focus on detecting loci that contribute additively to trait variation. Genetic interactions are often proposed as a contributing factor to trait variation, but the relative contribution of interactions to trait variation is a subject of debate. Here we use a very large cross between two yeast strains to accurately estimate the fraction of phenotypic variance due to pairwise QTL–QTL interactions for 20 quantitative traits. We find that this fraction is 9% on average, substantially less than the contribution of additive QTL (43%). Statistically significant QTL–QTL pairs typically have small individual effect sizes, but collectively explain 40% of the pairwise interaction variance. We show that pairwise interaction variance is largely explained by pairs of loci at least one of which has a significant additive effect. These results refine our understanding of the genetic architecture of quantitative traits and help guide future mapping studies. PMID:26537231

Postnatal width changes in the internal structures of the human mandible: a longitudinal three-dimensional cephalometric study using implants.

PubMed

Baumrind, S; Korn, E L

1992-12-01

This paper presents case-specific quantitative evidence of the systematic lateral displacement of metallic implants in the mandibles of treated and untreated human subjects between the ages of 8.5 and 15.5 years. This evidence appears to be consistent with the inference of small, but systematic increases in distance between the internal structures of the two sides of the osseous mandible during growth. Such a conclusion, however, is inconsistent with traditional beliefs that the internal structures of the mandibular symphysis fuse at the midline during the first post-natal year and remain dimensionally constant thereafter. We recently published evidence of statistically significant transverse displacement of metallic implants in the mandibular body region for 12 of 28 subjects for whom longitudinal data were available. Of the twelve subjects for whom statistically significant changes were observed, widening occurred in eleven cases and narrowing in one. Matching data are now available on concurrent ramus changes for 22 of the same 28 subjects, including 11 of the 12 for whom statistically significant width changes had previously been noted in the body region. In eight of these 11 subjects, statistically significant widening in the ramus region was also observed. No subject had statistically significant widening in the ramus region without also having statistically significant widening in the body region. No subject had statistically significant trans-ramus narrowing.

Application of pedagogy reflective in statistical methods course and practicum statistical methods

NASA Astrophysics Data System (ADS)

Julie, Hongki

2017-08-01

Subject Elementary Statistics, Statistical Methods and Statistical Methods Practicum aimed to equip students of Mathematics Education about descriptive statistics and inferential statistics. The students' understanding about descriptive and inferential statistics were important for students on Mathematics Education Department, especially for those who took the final task associated with quantitative research. In quantitative research, students were required to be able to present and describe the quantitative data in an appropriate manner, to make conclusions from their quantitative data, and to create relationships between independent and dependent variables were defined in their research. In fact, when students made their final project associated with quantitative research, it was not been rare still met the students making mistakes in the steps of making conclusions and error in choosing the hypothetical testing process. As a result, they got incorrect conclusions. This is a very fatal mistake for those who did the quantitative research. There were some things gained from the implementation of reflective pedagogy on teaching learning process in Statistical Methods and Statistical Methods Practicum courses, namely: 1. Twenty two students passed in this course and and one student did not pass in this course. 2. The value of the most accomplished student was A that was achieved by 18 students. 3. According all students, their critical stance could be developed by them, and they could build a caring for each other through a learning process in this course. 4. All students agreed that through a learning process that they undergo in the course, they can build a caring for each other.

Lack of quantitative training among early-career ecologists: a survey of the problem and potential solutions

PubMed Central

Ezard, Thomas H.G.; Jørgensen, Peter S.; Zimmerman, Naupaka; Chamberlain, Scott; Salguero-Gómez, Roberto; Curran, Timothy J.; Poisot, Timothée

2014-01-01

Proficiency in mathematics and statistics is essential to modern ecological science, yet few studies have assessed the level of quantitative training received by ecologists. To do so, we conducted an online survey. The 937 respondents were mostly early-career scientists who studied biology as undergraduates. We found a clear self-perceived lack of quantitative training: 75% were not satisfied with their understanding of mathematical models; 75% felt that the level of mathematics was “too low” in their ecology classes; 90% wanted more mathematics classes for ecologists; and 95% more statistics classes. Respondents thought that 30% of classes in ecology-related degrees should be focused on quantitative disciplines, which is likely higher than for most existing programs. The main suggestion to improve quantitative training was to relate theoretical and statistical modeling to applied ecological problems. Improving quantitative training will require dedicated, quantitative classes for ecology-related degrees that contain good mathematical and statistical practice. PMID:24688862

Correlation between quantitative traits and correlation between corresponding LOD scores: detection of pleiotropic effects.

PubMed

Ulgen, Ayse; Han, Zhihua; Li, Wentian

2003-12-31

We address the question of whether statistical correlations among quantitative traits lead to correlation of linkage results of these traits. Five measured quantitative traits (total cholesterol, fasting glucose, HDL cholesterol, blood pressure, and triglycerides), and one derived quantitative trait (total cholesterol divided by the HDL cholesterol) are used for phenotype correlation studies. Four of them are used for linkage analysis. We show that although correlation among phenotypes partially reflects the correlation among linkage analysis results, the LOD-score correlations are on average low. The most significant peaks found by using different traits do not often overlap. Studying covariances at specific locations in LOD scores may provide clues for further bivariate linkage analyses.

Quality Assessments of Long-Term Quantitative Proteomic Analysis of Breast Cancer Xenograft Tissues

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

Zhou, Jian-Ying; Chen, Lijun; Zhang, Bai

The identification of protein biomarkers requires large-scale analysis of human specimens to achieve statistical significance. In this study, we evaluated the long-term reproducibility of an iTRAQ (isobaric tags for relative and absolute quantification) based quantitative proteomics strategy using one channel for universal normalization across all samples. A total of 307 liquid chromatography tandem mass spectrometric (LC-MS/MS) analyses were completed, generating 107 one-dimensional (1D) LC-MS/MS datasets and 8 offline two-dimensional (2D) LC-MS/MS datasets (25 fractions for each set) for human-in-mouse breast cancer xenograft tissues representative of basal and luminal subtypes. Such large-scale studies require the implementation of robust metrics to assessmore » the contributions of technical and biological variability in the qualitative and quantitative data. Accordingly, we developed a quantification confidence score based on the quality of each peptide-spectrum match (PSM) to remove quantification outliers from each analysis. After combining confidence score filtering and statistical analysis, reproducible protein identification and quantitative results were achieved from LC-MS/MS datasets collected over a 16 month period.« less

Increased fibulin-1 plasma levels in polycystic ovary syndrome (PCOS) patients: possible contribution to the link between PCOS and cardiovascular risk.

PubMed

Scarinci, E; Tropea, A; Russo, G; Notaristefano, G; Messana, C; Alesiani, O; Fabozzi, S M; Lanzone, A; Apa, R

2018-04-21

To investigate a possible relation between fibulin-1 plasma levels and PCOS. ELISA quantitative determination of human fibulin-1. 50 women with PCOS and 40 control patients who attended the Unit of Human Reproductive Pathophysiology, Università Cattolica del Sacro Cuore, Rome, were enrolled. Ultrasonographic pelvic examinations, hormonal profile assays, oral tolerance test OGTT, lipid profile and ELISA quantitative determination of human fibulin-1 were performed. Fibulin-1 levels were found to be statistically significantly higher in PCOS patients than in matched control women. No statistically significant positive correlation was found between fibulin-1 and AUCi, HOMA-IR, total cholesterol, LDL, AMH, androstenedione and FAI, whereas a statistically significant positive correlation was found between fibulin-1 and 17OHP (p = 0.016) in the PCOS group. However, multivariable linear regression analysis showed that 17 OH P did not independently predict fibulin-1 levels (p = 0.089). Our data could contribute to explain the hypothesized increased cardiovascular risk and vascular damage in patients with PCOS. A better understanding of the cellular and molecular mechanisms involved in cardiometabolic disorders associated with PCOS is mandatory to identify new therapeutic strategies to eventually prevent the progression of cardiovascular diseases in these patients.

Bone measurements of infants with hyperbilirubinemia by quantitative ultrasound: the influence of phototherapy.

PubMed

Arıkan, Fatma İnci; Kara, Semra; Bilgin, Hüseyin; Özkan, Fatma; Bilge, Yıldız Dallar

2017-07-01

The purpose of the current study was to investigate the possible effects of phototherapy on bone status of term infants evaluated by measurement of tibial bone speed of sound (SOS). The phototherapy group (n = 30) consisted of children who had undergone phototherapy for at least 24 h and the control group (n = 30) comprised children who had not received phototherapy. Blood samples were obtained from all infants for serum calcium, phosphorus, magnesium, alkaline phosphatase, parathyroid hormone and vitamin D concentrations. The left tibial quantitative ultrasound (QUS) measurements were performed using a commercial device. There was no statistically significant difference between phototherapy-exposed and nonexposed infants in terms of Ca, P, ALP, PTH and vitamin D levels. Comparison of bone SOS between the phototherapy-exposed and control group revealed no statistically difference. Also, no significant difference in Z-score for SOS was observed between those with or without exposure. The data of our study indicate that phototherapy treatment has no impact on bone status in the hyperbilirubinemic infants. Although there is no statistically significant evidence of an excess risk of bone damage following phototherapy, studies with larger sample sizes and longer duration of follow-up are needed to gain a better understanding of its effects.

Statistical differences between relative quantitative molecular fingerprints from microbial communities.

PubMed

Portillo, M C; Gonzalez, J M

2008-08-01

Molecular fingerprints of microbial communities are a common method for the analysis and comparison of environmental samples. The significance of differences between microbial community fingerprints was analyzed considering the presence of different phylotypes and their relative abundance. A method is proposed by simulating coverage of the analyzed communities as a function of sampling size applying a Cramér-von Mises statistic. Comparisons were performed by a Monte Carlo testing procedure. As an example, this procedure was used to compare several sediment samples from freshwater ponds using a relative quantitative PCR-DGGE profiling technique. The method was able to discriminate among different samples based on their molecular fingerprints, and confirmed the lack of differences between aliquots from a single sample.

Qualitative and quantitative aspects of pain in lateral posterior thoracotomy patients.

PubMed

Xavier, Thaiza Teixeira; Torres, Gilson de Vasconcelos; da Rocha, Vera Maria

2006-01-01

Descriptive study that proposed to compare the qualitative and quantitative behavior of the pain in lateral posterior thoracotomy patients. The sample was consisted of 18 individuals with an average age of 44 years. The instruments used were physiotherapy evaluation form, numerical pain scale and McGill questionnaire for pain. The pain on the numerical pain scale was considered moderate(5) for both sexes. The descriptors of the McGill questionnaire choosen by the patients with higher frequency were: in the sensorial component, beat4, pointed1, shock2, final and pull2; in the afetive component, tired1, bored1, punishald1 and miserable1 and in the evaluative component was flat. The characteristics of pain in the sensorial group were more evidents on male group. No significant statistical difeferences were observed between quantitative answers concerning pain between the men and women. On the qualitative aspects , was observed an predominancy of the same descriptors of pain in afetive component for both sexes. Pain intensity was categorized as moderate. No significant statistical difference were observed between the pain on the post-operatory lateral posterior thoracotomy. These data demonstrate a necessity for an analysis with a larger study group.

Gene Level Meta-Analysis of Quantitative Traits by Functional Linear Models.

PubMed

Fan, Ruzong; Wang, Yifan; Boehnke, Michael; Chen, Wei; Li, Yun; Ren, Haobo; Lobach, Iryna; Xiong, Momiao

2015-08-01

Meta-analysis of genetic data must account for differences among studies including study designs, markers genotyped, and covariates. The effects of genetic variants may differ from population to population, i.e., heterogeneity. Thus, meta-analysis of combining data of multiple studies is difficult. Novel statistical methods for meta-analysis are needed. In this article, functional linear models are developed for meta-analyses that connect genetic data to quantitative traits, adjusting for covariates. The models can be used to analyze rare variants, common variants, or a combination of the two. Both likelihood-ratio test (LRT) and F-distributed statistics are introduced to test association between quantitative traits and multiple variants in one genetic region. Extensive simulations are performed to evaluate empirical type I error rates and power performance of the proposed tests. The proposed LRT and F-distributed statistics control the type I error very well and have higher power than the existing methods of the meta-analysis sequence kernel association test (MetaSKAT). We analyze four blood lipid levels in data from a meta-analysis of eight European studies. The proposed methods detect more significant associations than MetaSKAT and the P-values of the proposed LRT and F-distributed statistics are usually much smaller than those of MetaSKAT. The functional linear models and related test statistics can be useful in whole-genome and whole-exome association studies. Copyright © 2015 by the Genetics Society of America.

Characterization of breast lesion using T1-perfusion magnetic resonance imaging: Qualitative vs. quantitative analysis.

PubMed

Thakran, S; Gupta, P K; Kabra, V; Saha, I; Jain, P; Gupta, R K; Singh, A

2018-06-14

The objective of this study was to quantify the hemodynamic parameters using first pass analysis of T 1 -perfusion magnetic resonance imaging (MRI) data of human breast and to compare these parameters with the existing tracer kinetic parameters, semi-quantitative and qualitative T 1 -perfusion analysis in terms of lesion characterization. MRI of the breast was performed in 50 women (mean age, 44±11 [SD] years; range: 26-75) years with a total of 15 benign and 35 malignant breast lesions. After pre-processing, T 1 -perfusion MRI data was analyzed using qualitative approach by two radiologists (visual inspection of the kinetic curve into types I, II or III), semi-quantitative (characterization of kinetic curve types using empirical parameters), generalized-tracer-kinetic-model (tracer kinetic parameters) and first pass analysis (hemodynamic-parameters). Chi-squared test, t-test, one-way analysis-of-variance (ANOVA) using Bonferroni post-hoc test and receiver-operating-characteristic (ROC) curve were used for statistical analysis. All quantitative parameters except leakage volume (Ve), qualitative (type-I and III) and semi-quantitative curves (type-I and III) provided significant differences (P<0.05) between benign and malignant lesions. Kinetic parameters, particularly volume transfer coefficient (K trans ) provided a significant difference (P<0.05) between all grades except grade-II vs III. The hemodynamic parameter (relative-leakage-corrected-breast-blood-volume [rBBVcorr) provided a statistically significant difference (P<0.05) between all grades. It also provided highest sensitivity and specificity among all parameters in differentiation between different grades of malignant breast lesions. Quantitative parameters, particularly rBBVcorr and K trans provided similar sensitivity and specificity in differentiating benign from malignant breast lesions for this cohort. Moreover, rBBVcorr provided better differentiation between different grades of malignant breast lesions among all the parameters. Copyright © 2018. Published by Elsevier Masson SAS.

Infusion of Quantitative and Statistical Concepts into Biology Courses Does Not Improve Quantitative Literacy

ERIC Educational Resources Information Center

Beck, Christopher W.

2018-01-01

Multiple national reports have pushed for the integration of quantitative concepts into the context of disciplinary science courses. The aim of this study was to evaluate the quantitative and statistical literacy of biology students and explore learning gains when those skills were taught implicitly in the context of biology. I examined gains in…

Understanding quantitative research: part 1.

PubMed

Hoe, Juanita; Hoare, Zoë

This article, which is the first in a two-part series, provides an introduction to understanding quantitative research, basic statistics and terminology used in research articles. Critical appraisal of research articles is essential to ensure that nurses remain up to date with evidence-based practice to provide consistent and high-quality nursing care. This article focuses on developing critical appraisal skills and understanding the use and implications of different quantitative approaches to research. Part two of this article will focus on explaining common statistical terms and the presentation of statistical data in quantitative research.

Quantitative Skills, Critical Thinking, and Writing Mechanics in Blended versus Face-to-Face Versions of a Research Methods and Statistics Course

ERIC Educational Resources Information Center

Goode, Christopher T.; Lamoreaux, Marika; Atchison, Kristin J.; Jeffress, Elizabeth C.; Lynch, Heather L.; Sheehan, Elizabeth

2018-01-01

Hybrid or blended learning (BL) has been shown to be equivalent to or better than face-to-face (FTF) instruction in a broad variety of contexts. We randomly assigned students to either 50/50 BL or 100% FTF versions of a research methods and statistics in psychology course. Students who took the BL version of the course scored significantly lower…

Multivariate Analysis, Mass Balance Techniques, and Statistical Tests as Tools in Igneous Petrology: Application to the Sierra de las Cruces Volcanic Range (Mexican Volcanic Belt)

PubMed Central

Velasco-Tapia, Fernando

2014-01-01

Magmatic processes have usually been identified and evaluated using qualitative or semiquantitative geochemical or isotopic tools based on a restricted number of variables. However, a more complete and quantitative view could be reached applying multivariate analysis, mass balance techniques, and statistical tests. As an example, in this work a statistical and quantitative scheme is applied to analyze the geochemical features for the Sierra de las Cruces (SC) volcanic range (Mexican Volcanic Belt). In this locality, the volcanic activity (3.7 to 0.5 Ma) was dominantly dacitic, but the presence of spheroidal andesitic enclaves and/or diverse disequilibrium features in majority of lavas confirms the operation of magma mixing/mingling. New discriminant-function-based multidimensional diagrams were used to discriminate tectonic setting. Statistical tests of discordancy and significance were applied to evaluate the influence of the subducting Cocos plate, which seems to be rather negligible for the SC magmas in relation to several major and trace elements. A cluster analysis following Ward's linkage rule was carried out to classify the SC volcanic rocks geochemical groups. Finally, two mass-balance schemes were applied for the quantitative evaluation of the proportion of the end-member components (dacitic and andesitic magmas) in the comingled lavas (binary mixtures). PMID:24737994

Adaptive Statistical Iterative Reconstruction-V Versus Adaptive Statistical Iterative Reconstruction: Impact on Dose Reduction and Image Quality in Body Computed Tomography.

PubMed

Gatti, Marco; Marchisio, Filippo; Fronda, Marco; Rampado, Osvaldo; Faletti, Riccardo; Bergamasco, Laura; Ropolo, Roberto; Fonio, Paolo

The aim of this study was to evaluate the impact on dose reduction and image quality of the new iterative reconstruction technique: adaptive statistical iterative reconstruction (ASIR-V). Fifty consecutive oncologic patients acted as case controls undergoing during their follow-up a computed tomography scan both with ASIR and ASIR-V. Each study was analyzed in a double-blinded fashion by 2 radiologists. Both quantitative and qualitative analyses of image quality were conducted. Computed tomography scanner radiation output was 38% (29%-45%) lower (P < 0.0001) for the ASIR-V examinations than for the ASIR ones. The quantitative image noise was significantly lower (P < 0.0001) for ASIR-V. Adaptive statistical iterative reconstruction-V had a higher performance for the subjective image noise (P = 0.01 for 5 mm and P = 0.009 for 1.25 mm), the other parameters (image sharpness, diagnostic acceptability, and overall image quality) being similar (P > 0.05). Adaptive statistical iterative reconstruction-V is a new iterative reconstruction technique that has the potential to provide image quality equal to or greater than ASIR, with a dose reduction around 40%.

The challenge of identifying greenhouse gas-induced climatic change

NASA Technical Reports Server (NTRS)

Maccracken, Michael C.

1992-01-01

Meeting the challenge of identifying greenhouse gas-induced climatic change involves three steps. First, observations of critical variables must be assembled, evaluated, and analyzed to determine that there has been a statistically significant change. Second, reliable theoretical (model) calculations must be conducted to provide a definitive set of changes for which to search. Third, a quantitative and statistically significant association must be made between the projected and observed changes to exclude the possibility that the changes are due to natural variability or other factors. This paper provides a qualitative overview of scientific progress in successfully fulfilling these three steps.

Quantitative impact of pediatric sinus surgery on facial growth.

PubMed

Senior, B; Wirtschafter, A; Mai, C; Becker, C; Belenky, W

2000-11-01

To quantitatively evaluate the long-term impact of sinus surgery on paranasal sinus development in the pediatric patient. Longitudinal review of eight pediatric patients treated with unilateral sinus surgery for periorbital or orbital cellulitis with an average follow-up of 6.9 years. Control subjects consisted of two groups, 9 normal adult patients with no computed tomographic evidence of sinusitis and 10 adult patients with scans consistent with sinusitis and a history of sinus-related symptoms extending to childhood. Application of computed tomography (CT) volumetrics, a technique allowing for precise calculation of volumes using thinly cut CT images, to the study and control groups. Paired Student t test analyses of side-to-side volume comparisons in the normal patients, patients with sinusitis, and patients who had surgery revealed no statistically significant differences. Comparisons between the orbital volumes of patients who did and did not have surgery revealed a statistically significant increase in orbital volume in patients who had surgery. Only minimal changes in facial volume measurements have been found, confirming clinical impressions that sinus surgery in children is safe and without significant cosmetic sequelae.

Quantitative 3D analysis of bone in hip osteoarthritis using clinical computed tomography.

PubMed

Turmezei, Tom D; Treece, Graham M; Gee, Andrew H; Fotiadou, Anastasia F; Poole, Kenneth E S

2016-07-01

To assess the relationship between proximal femoral cortical bone thickness and radiological hip osteoarthritis using quantitative 3D analysis of clinical computed tomography (CT) data. Image analysis was performed on clinical CT imaging data from 203 female volunteers with a technique called cortical bone mapping (CBM). Colour thickness maps were created for each proximal femur. Statistical parametric mapping was performed to identify statistically significant differences in cortical bone thickness that corresponded with the severity of radiological hip osteoarthritis. Kellgren and Lawrence (K&L) grade, minimum joint space width (JSW) and a novel CT-based osteophyte score were also blindly assessed from the CT data. For each increase in K&L grade, cortical thickness increased by up to 25 % in distinct areas of the superolateral femoral head-neck junction and superior subchondral bone plate. For increasing severity of CT osteophytes, the increase in cortical thickness was more circumferential, involving a wider portion of the head-neck junction, with up to a 7 % increase in cortical thickness per increment in score. Results were not significant for minimum JSW. These findings indicate that quantitative 3D analysis of the proximal femur can identify changes in cortical bone thickness relevant to structural hip osteoarthritis. • CT is being increasingly used to assess bony involvement in osteoarthritis • CBM provides accurate and reliable quantitative analysis of cortical bone thickness • Cortical bone is thicker at the superior femoral head-neck with worse osteoarthritis • Regions of increased thickness co-locate with impingement and osteophyte formation • Quantitative 3D bone analysis could enable clinical disease prediction and therapy development.

The Matching Relation and Situation-Specific Bias Modulation in Professional Football Play Selection

PubMed Central

Stilling, Stephanie T; Critchfield, Thomas S

2010-01-01

The utility of a quantitative model depends on the extent to which its fitted parameters vary systematically with environmental events of interest. Professional football statistics were analyzed to determine whether play selection (passing versus rushing plays) could be accounted for with the generalized matching equation, and in particular whether variations in play selection across game situations would manifest as changes in the equation's fitted parameters. Statistically significant changes in bias were found for each of five types of game situations; no systematic changes in sensitivity were observed. Further analyses suggested relationships between play selection bias and both turnover probability (which can be described in terms of punishment) and yards-gained variance (which can be described in terms of variable-magnitude reinforcement schedules). The present investigation provides a useful demonstration of association between face-valid, situation-specific effects in a domain of everyday interest, and a theoretically important term of a quantitative model of behavior. Such associations, we argue, are an essential focus in translational extensions of quantitative models. PMID:21119855

Teaching Statistics in Biology: Using Inquiry-based Learning to Strengthen Understanding of Statistical Analysis in Biology Laboratory Courses

PubMed Central

2008-01-01

There is an increasing need for students in the biological sciences to build a strong foundation in quantitative approaches to data analyses. Although most science, engineering, and math field majors are required to take at least one statistics course, statistical analysis is poorly integrated into undergraduate biology course work, particularly at the lower-division level. Elements of statistics were incorporated into an introductory biology course, including a review of statistics concepts and opportunity for students to perform statistical analysis in a biological context. Learning gains were measured with an 11-item statistics learning survey instrument developed for the course. Students showed a statistically significant 25% (p < 0.005) increase in statistics knowledge after completing introductory biology. Students improved their scores on the survey after completing introductory biology, even if they had previously completed an introductory statistics course (9%, improvement p < 0.005). Students retested 1 yr after completing introductory biology showed no loss of their statistics knowledge as measured by this instrument, suggesting that the use of statistics in biology course work may aid long-term retention of statistics knowledge. No statistically significant differences in learning were detected between male and female students in the study. PMID:18765754

Public and patient involvement in quantitative health research: A statistical perspective.

PubMed

Hannigan, Ailish

2018-06-19

The majority of studies included in recent reviews of impact for public and patient involvement (PPI) in health research had a qualitative design. PPI in solely quantitative designs is underexplored, particularly its impact on statistical analysis. Statisticians in practice have a long history of working in both consultative (indirect) and collaborative (direct) roles in health research, yet their perspective on PPI in quantitative health research has never been explicitly examined. To explore the potential and challenges of PPI from a statistical perspective at distinct stages of quantitative research, that is sampling, measurement and statistical analysis, distinguishing between indirect and direct PPI. Statistical analysis is underpinned by having a representative sample, and a collaborative or direct approach to PPI may help achieve that by supporting access to and increasing participation of under-represented groups in the population. Acknowledging and valuing the role of lay knowledge of the context in statistical analysis and in deciding what variables to measure may support collective learning and advance scientific understanding, as evidenced by the use of participatory modelling in other disciplines. A recurring issue for quantitative researchers, which reflects quantitative sampling methods, is the selection and required number of PPI contributors, and this requires further methodological development. Direct approaches to PPI in quantitative health research may potentially increase its impact, but the facilitation and partnership skills required may require further training for all stakeholders, including statisticians. © 2018 The Authors Health Expectations published by John Wiley & Sons Ltd.

77 FR 36489 - Agency Information Collection Activities: Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-19

... collection methods, including interviews and research, to inform the design, development, and implementation.... For example, information collected from consumers will help the CFPB to design model forms... used for quantitative information collections that are designed to yield statistically significant...

Critical Thinking in the Business Classroom

ERIC Educational Resources Information Center

Reid, Joanne R.; Anderson, Phyllis R.

2012-01-01

A minicourse in critical thinking was implemented to improve student outcomes in two sessions of a senior-level business course at a Midwestern university. Statistical analyses of two quantitative assessments revealed significant improvements in critical thinking skills. Improvements in student outcomes in case studies and computerized business…

Myths and Misconceptions about Using Qualitative Methods in Assessment

ERIC Educational Resources Information Center

Harper, Shaun R.; Kuh, George D.

2007-01-01

The value of qualitative assessment approaches has been underestimated primarily because they are often juxtaposed against long-standing quantitative traditions and the widely accepted premise that the best research produces generalizable and statistically significant findings. Institutional researchers avoid qualitative methods for at least three…

Microscopes and computers combined for analysis of chromosomes

NASA Technical Reports Server (NTRS)

Butler, J. W.; Butler, M. K.; Stroud, A. N.

1969-01-01

Scanning machine CHLOE, developed for photographic use, is combined with a digital computer to obtain quantitative and statistically significant data on chromosome shapes, distribution, density, and pairing. CHLOE permits data acquisition about a chromosome complement to be obtained two times faster than by manual pairing.

Assessing signal-to-noise in quantitative proteomics: multivariate statistical analysis in DIGE experiments.

PubMed

Friedman, David B

2012-01-01

All quantitative proteomics experiments measure variation between samples. When performing large-scale experiments that involve multiple conditions or treatments, the experimental design should include the appropriate number of individual biological replicates from each condition to enable the distinction between a relevant biological signal from technical noise. Multivariate statistical analyses, such as principal component analysis (PCA), provide a global perspective on experimental variation, thereby enabling the assessment of whether the variation describes the expected biological signal or the unanticipated technical/biological noise inherent in the system. Examples will be shown from high-resolution multivariable DIGE experiments where PCA was instrumental in demonstrating biologically significant variation as well as sample outliers, fouled samples, and overriding technical variation that would not be readily observed using standard univariate tests.

Selecting the most appropriate inferential statistical test for your quantitative research study.

PubMed

Bettany-Saltikov, Josette; Whittaker, Victoria Jane

2014-06-01

To discuss the issues and processes relating to the selection of the most appropriate statistical test. A review of the basic research concepts together with a number of clinical scenarios is used to illustrate this. Quantitative nursing research generally features the use of empirical data which necessitates the selection of both descriptive and statistical tests. Different types of research questions can be answered by different types of research designs, which in turn need to be matched to a specific statistical test(s). Discursive paper. This paper discusses the issues relating to the selection of the most appropriate statistical test and makes some recommendations as to how these might be dealt with. When conducting empirical quantitative studies, a number of key issues need to be considered. Considerations for selecting the most appropriate statistical tests are discussed and flow charts provided to facilitate this process. When nursing clinicians and researchers conduct quantitative research studies, it is crucial that the most appropriate statistical test is selected to enable valid conclusions to be made. © 2013 John Wiley & Sons Ltd.

Identifying irregularly shaped crime hot-spots using a multiobjective evolutionary algorithm

NASA Astrophysics Data System (ADS)

Wu, Xiaolan; Grubesic, Tony H.

2010-12-01

Spatial cluster detection techniques are widely used in criminology, geography, epidemiology, and other fields. In particular, spatial scan statistics are popular and efficient techniques for detecting areas of elevated crime or disease events. The majority of spatial scan approaches attempt to delineate geographic zones by evaluating the significance of clusters using likelihood ratio statistics tested with the Poisson distribution. While this can be effective, many scan statistics give preference to circular clusters, diminishing their ability to identify elongated and/or irregular shaped clusters. Although adjusting the shape of the scan window can mitigate some of these problems, both the significance of irregular clusters and their spatial structure must be accounted for in a meaningful way. This paper utilizes a multiobjective evolutionary algorithm to find clusters with maximum significance while quantitatively tracking their geographic structure. Crime data for the city of Cincinnati are utilized to demonstrate the advantages of the new approach and highlight its benefits versus more traditional scan statistics.

A new strategy for statistical analysis-based fingerprint establishment: Application to quality assessment of Semen sojae praeparatum.

PubMed

Guo, Hui; Zhang, Zhen; Yao, Yuan; Liu, Jialin; Chang, Ruirui; Liu, Zhao; Hao, Hongyuan; Huang, Taohong; Wen, Jun; Zhou, Tingting

2018-08-30

Semen sojae praeparatum with homology of medicine and food is a famous traditional Chinese medicine. A simple and effective quality fingerprint analysis, coupled with chemometrics methods, was developed for quality assessment of Semen sojae praeparatum. First, similarity analysis (SA) and hierarchical clusting analysis (HCA) were applied to select the qualitative markers, which obviously influence the quality of Semen sojae praeparatum. 21 chemicals were selected and characterized by high resolution ion trap/time-of-flight mass spectrometry (LC-IT-TOF-MS). Subsequently, principal components analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were conducted to select the quantitative markers of Semen sojae praeparatum samples from different origins. Moreover, 11 compounds with statistical significance were determined quantitatively, which provided an accurate and informative data for quality evaluation. This study proposes a new strategy for "statistic analysis-based fingerprint establishment", which would be a valuable reference for further study. Copyright © 2018 Elsevier Ltd. All rights reserved.

Methodological reporting in qualitative, quantitative, and mixed methods health services research articles.

PubMed

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

2012-04-01

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. All empirical articles (n = 1,651) published between 2003 and 2007 from four top-ranked health services journals. 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. 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 (χ(2) (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 (χ(2) (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). 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. © Health Research and Educational Trust.

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

Counting Better? An Examination of the Impact of Quantitative Method Teaching on Statistical Anxiety and Confidence

ERIC Educational Resources Information Center

Chamberlain, John Martyn; Hillier, John; Signoretta, Paola

2015-01-01

This article reports the results of research concerned with students' statistical anxiety and confidence to both complete and learn to complete statistical tasks. Data were collected at the beginning and end of a quantitative method statistics module. Students recognised the value of numeracy skills but felt they were not necessarily relevant for…

Quantification and statistical significance analysis of group separation in NMR-based metabonomics studies

PubMed Central

Goodpaster, Aaron M.; Kennedy, Michael A.

2015-01-01

Currently, no standard metrics are used to quantify cluster separation in PCA or PLS-DA scores plots for metabonomics studies or to determine if cluster separation is statistically significant. Lack of such measures makes it virtually impossible to compare independent or inter-laboratory studies and can lead to confusion in the metabonomics literature when authors putatively identify metabolites distinguishing classes of samples based on visual and qualitative inspection of scores plots that exhibit marginal separation. While previous papers have addressed quantification of cluster separation in PCA scores plots, none have advocated routine use of a quantitative measure of separation that is supported by a standard and rigorous assessment of whether or not the cluster separation is statistically significant. Here quantification and statistical significance of separation of group centroids in PCA and PLS-DA scores plots are considered. The Mahalanobis distance is used to quantify the distance between group centroids, and the two-sample Hotelling's T2 test is computed for the data, related to an F-statistic, and then an F-test is applied to determine if the cluster separation is statistically significant. We demonstrate the value of this approach using four datasets containing various degrees of separation, ranging from groups that had no apparent visual cluster separation to groups that had no visual cluster overlap. Widespread adoption of such concrete metrics to quantify and evaluate the statistical significance of PCA and PLS-DA cluster separation would help standardize reporting of metabonomics data. PMID:26246647

Comparing identified and statistically significant lipids and polar metabolites in 15-year old serum and dried blood spot samples for longitudinal studies: Comparing lipids and metabolites in serum and DBS samples

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

Kyle, Jennifer E.; Casey, Cameron P.; Stratton, Kelly G.

The use of dried blood spots (DBS) has many advantages over traditional plasma and serum samples such as smaller blood volume required, storage at room temperature, and ability for sampling in remote locations. However, understanding the robustness of different analytes in DBS samples is essential, especially in older samples collected for longitudinal studies. Here we analyzed DBS samples collected in 2000-2001 and stored at room temperature and compared them to matched serum samples stored at -80°C to determine if they could be effectively used as specific time points in a longitudinal study following metabolic disease. Four hundred small molecules weremore » identified in both the serum and DBS samples using gas chromatograph-mass spectrometry (GC-MS), liquid chromatography-MS (LC-MS) and LC-ion mobility spectrometry-MS (LC-IMS-MS). The identified polar metabolites overlapped well between the sample types, though only one statistically significant polar metabolite in a case-control study was conserved, indicating degradation occurs in the DBS samples affecting quantitation. Differences in the lipid identifications indicated that some oxidation occurs in the DBS samples. However, thirty-six statistically significant lipids correlated in both sample types indicating that lipid quantitation was more stable across the sample types.« less

Teacher Contract Non-Renewal: Midwest, Rocky Mountains, and Southeast

ERIC Educational Resources Information Center

Nixon, Andy; Dam, Margaret; Packard, Abbot L.

2012-01-01

This quantitative study investigated reasons that school principals recommend non-renewal of probationary teachers' contracts. Principal survey results from three regions of the US (Midwest, Rocky Mountains, & Southeast) were analyzed using the Kruskal-Wallis and Mann-Whitney U statistical procedures, while significance was tested applying a…

Doctoral training in statistics, measurement, and methodology in psychology: replication and extension of Aiken, West, Sechrest, and Reno's (1990) survey of PhD programs in North America.

PubMed

Aiken, Leona S; West, Stephen G; Millsap, Roger E

2008-01-01

In a survey of all PhD programs in psychology in the United States and Canada, the authors documented the quantitative methodology curriculum (statistics, measurement, and research design) to examine the extent to which innovations in quantitative methodology have diffused into the training of PhDs in psychology. In all, 201 psychology PhD programs (86%) participated. This survey replicated and extended a previous survey (L. S. Aiken, S. G. West, L. B. Sechrest, & R. R. Reno, 1990), permitting examination of curriculum development. Most training supported laboratory and not field research. The median of 1.6 years of training in statistics and measurement was mainly devoted to the modally 1-year introductory statistics course, leaving little room for advanced study. Curricular enhancements were noted in statistics and to a minor degree in measurement. Additional coverage of both fundamental and innovative quantitative methodology is needed. The research design curriculum has largely stagnated, a cause for great concern. Elite programs showed no overall advantage in quantitative training. Forces that support curricular innovation are characterized. Human capital challenges to quantitative training, including recruiting and supporting young quantitative faculty, are discussed. Steps must be taken to bring innovations in quantitative methodology into the curriculum of PhD programs in psychology. PsycINFO Database Record (c) 2008 APA, all rights reserved.

Visual and Quantitative Assessment of Coronary Stenoses at Angiography Versus Fractional Flow Reserve: The Impact of Risk Factors.

PubMed

Adjedj, Julien; Xaplanteris, Panagiotis; Toth, Gabor; Ferrara, Angela; Pellicano, Mariano; Ciccarelli, Giovanni; Floré, Vincent; Barbato, Emanuele; De Bruyne, Bernard

2017-07-01

The correlation between angiographic assessment of coronary stenoses and fractional flow reserve (FFR) is weak. Whether and how risk factors impact the diagnostic accuracy of angiography is unknown. We sought to evaluate the diagnostic accuracy of angiography by visual estimate and by quantitative coronary angiography when compared with FFR and evaluate the influence of risk factors (RF) on this accuracy. In 1382 coronary stenoses (1104 patients), percent diameter stenosis by visual estimation (DS VE ) and by quantitative coronary angiography (DS QCA ) was compared with FFR. Patients were divided into 4 subgroups, according to the presence of RFs, and the relationship between DS VE , DS QCA , and FFR was analyzed. Overall, DS VE was significantly higher than DS QCA ( P <0.0001); nonetheless, when examined by strata of DS, DS VE was significantly smaller than DS QCA in mild stenoses, although the reverse held true for severe stenoses. Compared with FFR, a large scatter was observed for both DS VE and DS QCA . When using a dichotomous FFR value of 0.80, C statistic was significantly higher for DS VE than for DS QCA (0.712 versus 0.640, respectively; P <0.001). C statistics for DS VE decreased progressively as RFs accumulated (0.776 for ≤1 RF, 0.750 for 2 RFs, 0.713 for 3 RFs and 0.627 for ≥4 RFs; P =0.0053). In addition, in diabetics, the relationship between FFR and angiographic indices was particularly weak (C statistics: 0.524 for DS VE and 0.511 for DS QCA ). Overall, DS VE has a better diagnostic accuracy than DS QCA to predict the functional significance of coronary stenosis. The predictive accuracy of angiography is moderate in patients with ≤1 RFs, but weakens as RFs accumulate, especially in diabetics. © 2017 American Heart Association, Inc.

The Harm Done to Reproducibility by the Culture of Null Hypothesis Significance Testing.

PubMed

Lash, Timothy L

2017-09-15

In the last few years, stakeholders in the scientific community have raised alarms about a perceived lack of reproducibility of scientific results. In reaction, guidelines for journals have been promulgated and grant applicants have been asked to address the rigor and reproducibility of their proposed projects. Neither solution addresses a primary culprit, which is the culture of null hypothesis significance testing that dominates statistical analysis and inference. In an innovative research enterprise, selection of results for further evaluation based on null hypothesis significance testing is doomed to yield a low proportion of reproducible results and a high proportion of effects that are initially overestimated. In addition, the culture of null hypothesis significance testing discourages quantitative adjustments to account for systematic errors and quantitative incorporation of prior information. These strategies would otherwise improve reproducibility and have not been previously proposed in the widely cited literature on this topic. Without discarding the culture of null hypothesis significance testing and implementing these alternative methods for statistical analysis and inference, all other strategies for improving reproducibility will yield marginal gains at best. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Assessing the status of airline safety culture and its relationship to key employee attitudes

NASA Astrophysics Data System (ADS)

Owen, Edward L.

The need to identify the factors that influence the overall safety environment and compliance with safety procedures within airline operations is substantial. This study examines the relationships between job satisfaction, the overall perception of the safety culture, and compliance with safety rules and regulations of airline employees working in flight operations. A survey questionnaire administered via the internet gathered responses which were converted to numerical values for quantitative analysis. The results were grouped to provide indications of overall average levels in each of the three categories, satisfaction, perceptions, and compliance. Correlations between data in the three sets were tested for statistical significance using two-sample t-tests assuming equal variances. Strong statistical significance was found between job satisfaction and compliance with safety rules and between perceptions of the safety environment and safety compliance. The relationship between job satisfaction and safety perceptions did not show strong statistical significance.

Quantitative evaluation of lumbar intervertebral disc degeneration by axial T2* mapping.

PubMed

Huang, Leitao; Liu, Yuan; Ding, Yi; Wu, Xia; Zhang, Ning; Lai, Qi; Zeng, Xianjun; Wan, Zongmiao; Dai, Min; Zhang, Bin

2017-12-01

To quantitatively evaluate the clinical value and demonstrate the potential benefits of biochemical axial T2* mapping-based grading of early stages of degenerative disc disease (DDD) using 3.0-T magnetic resonance imaging (MRI) in a clinical setting.Fifty patients with low back pain and 20 healthy volunteers (control) underwent standard MRI protocols including axial T2* mapping. All the intervertebral discs (IVDs) were classified morphologically. Lumbar IVDs were graded using Pfirrmann score (I to IV). The T2* values of the anterior annulus fibrosus (AF), posterior AF, and nucleus pulposus (NP) of each lumbar IVD were measured. The differences between groups were analyzed regarding specific T2* pattern at different regions of interest.The T2* values of the NP and posterior AF in the patient group were significantly lower than those in the control group (P < .01). The T2* value of the anterior AF was not significantly different between the patients and the controls (P > .05). The mean T2*values of the lumbar IVD in the patient group were significantly lower, especially the posterior AF, followed by the NP, and finally, the anterior AF. In the anterior AF, comparison of grade I with grade III and grade I with grade IV showed statistically significant differences (P = .07 and P = .08, respectively). Similarly, in the NP, comparison of grade I with grade III, grade I with grade IV, grade II with grade III, and grade II with grade IV showed statistically significant differences (P < .001). In the posterior AF, comparison of grade II with grade IV showed a statistically significant difference (P = .032). T2 values decreased linearly with increasing degeneration based on the Pfirrmann scoring system (ρ < -0.5, P < .001).Changes in the T2* value can signify early degenerative IVD diseases. Hence, T2* mapping can be used as a diagnostic tool for quantitative assessment of IVD degeneration. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

Quantitative evaluation of lumbar intervertebral disc degeneration by axial T2∗ mapping

PubMed Central

Huang, Leitao; Liu, Yuan; Ding, Yi; Wu, Xia; Zhang, Ning; Lai, Qi; Zeng, Xianjun; Wan, Zongmiao; Dai, Min; Zhang, Bin

2017-01-01

Abstract To quantitatively evaluate the clinical value and demonstrate the potential benefits of biochemical axial T2∗ mapping-based grading of early stages of degenerative disc disease (DDD) using 3.0-T magnetic resonance imaging (MRI) in a clinical setting. Fifty patients with low back pain and 20 healthy volunteers (control) underwent standard MRI protocols including axial T2∗ mapping. All the intervertebral discs (IVDs) were classified morphologically. Lumbar IVDs were graded using Pfirrmann score (I to IV). The T2∗ values of the anterior annulus fibrosus (AF), posterior AF, and nucleus pulposus (NP) of each lumbar IVD were measured. The differences between groups were analyzed regarding specific T2∗ pattern at different regions of interest. The T2∗ values of the NP and posterior AF in the patient group were significantly lower than those in the control group (P < .01). The T2∗ value of the anterior AF was not significantly different between the patients and the controls (P > .05). The mean T2∗values of the lumbar IVD in the patient group were significantly lower, especially the posterior AF, followed by the NP, and finally, the anterior AF. In the anterior AF, comparison of grade I with grade III and grade I with grade IV showed statistically significant differences (P = .07 and P = .08, respectively). Similarly, in the NP, comparison of grade I with grade III, grade I with grade IV, grade II with grade III, and grade II with grade IV showed statistically significant differences (P < .001). In the posterior AF, comparison of grade II with grade IV showed a statistically significant difference (P = .032). T2∗ values decreased linearly with increasing degeneration based on the Pfirrmann scoring system (ρ < −0.5, P < .001). Changes in the T2∗ value can signify early degenerative IVD diseases. Hence, T2∗ mapping can be used as a diagnostic tool for quantitative assessment of IVD degeneration. PMID:29390547

Medical statistics and hospital medicine: the case of the smallpox vaccination.

PubMed

Rusnock, Andrea

2007-01-01

Between 1799 and 1806, trials of vaccination to determine its safety and efficacy were undertaken in hospitals in London, Paris, Vienna, and Boston. These trials were among the first instances of formal hospital evaluations of a medical procedure and signal a growing acceptance of a relatively new approach to medical practice. These early evaluations of smallpox vaccination also relied on descriptive and quantitative accounts, as well as probabilistic analyses, and thus occupy a significant, yet hitherto unexamined, place in the history of medical statistics.

Non-Earth-centric life detection

NASA Technical Reports Server (NTRS)

Conrad, P. G.; Nealson, K. H.

2000-01-01

Our hope is that life will, bit by bit, reveal the clues that will allow us to piece together enough evidence to recognize it whenever and however it presents itself. Indisputable evidence is measurable, statistically meaningful and independent of the nature of the life it defines. That the evidence for life be measurable is a fundamental requirement of the scientific method, as is the requirement for statistical significance, and this quantitation is what enables us to differentiate the measurable criteria of candidate biosignatures from a background (host environment).

Quantitative EEG abnormalities in persons with "pure" epileptic predisposition without epilepsy: a low resolution electromagnetic tomography (LORETA) study.

PubMed

Puskás, S; Bessenyei, M; Fekete, I; Hollódy, K; Clemens, B

2010-09-01

Epileptic predisposition means genetically determined, increased seizure susceptibility. Neurophysiological evaluation of this condition is still lacking. In order to investigate "pure epileptic predisposition" (without epilepsy) in this pilot study the authors prospectively recruited ten persons who displayed generalized tonic-clonic seizures precipitated by 24 or more hours of sleep deprivation but were healthy in any other respects. 21-channel EEGs were recorded in the morning, in the waking state, after a night of sufficient sleep in the interictal period. For each person, a total of 120s artifact-free EEG was processed to low resolution electromagnetic tomography (LORETA) analysis. LORETA activity (Ampers/meters squared) was computed for 2394 voxels, 19 active electrodes and 1Hz very narrow bands from 1 to 25Hz. The data were compressed into four frequency bands (delta: 0.5-4.0Hz, theta: 4.5-8.0Hz, alpha: 8.5-12.0Hz, beta: 12.5-25.0Hz) and projected onto the MRI figures of a digitized standard brain atlas. The band-related LORETA results were compared to those of ten, age- and sex-matched healthy persons using independent t-tests. p<0.01 differences were accepted as statistically significant. Statistically significant decrease of alpha activity was found in widespread, medial and lateral parts of the cortex above the level of the basal ganglia. Maximum alpha decrease and statistically significant beta decrease were found in the left precuneus. Statistically not significant differences were delta increase in the medial-basal frontal area and theta increase in the same area and in the basal temporal area. The significance of alpha decrease in the patient group remains enigmatic. beta decrease presumably reflects non-specific dysfunction of the cortex. Prefrontal delta and theta increase might have biological meaning despite the lack of statistical significance: these findings are topographically similar to those reported in idiopathic generalized epilepsy in previous investigations. Quantitative EEG characteristics of the genetically determined epilepsy predisposition were given in terms of frequency bands and anatomical distribution. Copyright 2010 Elsevier B.V. All rights reserved.

Effects of Peer Tutoring on Reading Self-Concept

ERIC Educational Resources Information Center

Flores, Marta; Duran, David

2013-01-01

This study investigates the development of the Reading Self-Concept and of the mechanisms underlying it, within a framework of a reading programme based on peer tutoring. The multiple methodological design adopted allowed for a quantitative approach which showed statistically significant changes in the Reading Self-Concept of those students who…

Using Self-Regulated Learning Strategies to Develop Students' Multicultural Counseling Competency

ERIC Educational Resources Information Center

Zeleke, Waganesh A.; Karayigit, Cebrail; Myers-Brooks, Kaitlyn

2018-01-01

This study examines the effect of self-regulated learning strategies on students' multicultural competency development. Quantitative and qualitative data were collected from 26 students who took a semester-long multicultural counseling course. Results show statistically significant improvement in students' multicultural awareness and knowledge and…

The Impact of a Nutritional Intervention Program on Academics in Selected Public Schools

ERIC Educational Resources Information Center

Rich, Stacy

2011-01-01

The purpose of this quantitative quasi-experimental study is to examine the effectiveness of the "Healthy Kids, Smart Kids" intervention program on academics. Extant data will be used to determine if a statistically significant difference in academics exist between experimental schools implementing the "Healthy Kids, Smart…

An Investigation of School Counselor Self-Efficacy with English Language Learners

ERIC Educational Resources Information Center

Johnson, Leonissa V.; Ziomek-Daigle, Jolie; Haskins, Natoya Hill; Paisley, Pamela O.

2017-01-01

This exploratory quantitative study described school counselors' self-efficacy with English language learners. Findings suggest that school counselors with exposure to and experiences with English language learners have higher levels of self-efficacy. Statistically significant and practical differences in self-efficacy were apparent by race, U.S.…

Investigation of Millennial Students' Responses to a Shelter-in-Place Experience

ERIC Educational Resources Information Center

Johnson, Thomas C.; Frick, Melodie H.

2016-01-01

This study investigated millennial students' responses to an armed gunman threat and shelter-in-place warnings that occurred on a university campus. Using descriptive statistics and quantitative analysis, several significant differences were found for students' responses for sheltering-in-place and engaging in protective behaviors. Baxter Magolda'…

Predicting Teacher Job Satisfaction Based on Principals' Instructional Supervision Behaviours: A Study of Turkish Teachers

ERIC Educational Resources Information Center

Ilgan, Abdurrahman; Parylo, Oksana; Sungu, Hilmi

2015-01-01

This quantitative research examined instructional supervision behaviours of school principals as a predictor of teacher job satisfaction through the analysis of Turkish teachers' perceptions of principals' instructional supervision behaviours. There was a statistically significant difference found between the teachers' job satisfaction level and…

Quantitatively Assessing Reported Crime versus Enrollment among Selected Higher Education Institutions

ERIC Educational Resources Information Center

Doss, Daniel; Lackey, Hilliard; McElreath, David; Gokaraju, Balakrishna; Tesiero, Raymond; Jones, Don; Lusk, Glenna

2017-01-01

This study uses multiple regressions to examine campus safety and campus security from the perspective of societal crime that occurs external to an institution of higher education versus institutional enrollment. The findings herein showed one statistically significant outcome involving the crime of aggravated assault. Student affairs and other…

Effect Sizes in Gifted Education Research

ERIC Educational Resources Information Center

Gentry, Marcia; Peters, Scott J.

2009-01-01

Recent calls for reporting and interpreting effect sizes have been numerous, with the 5th edition of the "Publication Manual of the American Psychological Association" (2001) calling for the inclusion of effect sizes to interpret quantitative findings. Many top journals have required that effect sizes accompany claims of statistical significance.…

Content and Citation Analyses of "Public Relations Review."

ERIC Educational Resources Information Center

Morton, Linda P.; Lin, Li-Yun

1995-01-01

Analyzes 161 cited and 177 uncited articles published in "Public Relations Review" (1975-93) to determine if 3 independent variables--research methods, type of statistics, and topics--influenced whether or not articles were cited in other research articles. Finds significant differences between quantitative and qualitative research methods but not…

A quantitative study of nanoparticle skin penetration with interactive segmentation.

PubMed

Lee, Onseok; Lee, See Hyun; Jeong, Sang Hoon; Kim, Jaeyoung; Ryu, Hwa Jung; Oh, Chilhwan; Son, Sang Wook

2016-10-01

In the last decade, the application of nanotechnology techniques has expanded within diverse areas such as pharmacology, medicine, and optical science. Despite such wide-ranging possibilities for implementation into practice, the mechanisms behind nanoparticle skin absorption remain unknown. Moreover, the main mode of investigation has been qualitative analysis. Using interactive segmentation, this study suggests a method of objectively and quantitatively analyzing the mechanisms underlying the skin absorption of nanoparticles. Silica nanoparticles (SNPs) were assessed using transmission electron microscopy and applied to the human skin equivalent model. Captured fluorescence images of this model were used to evaluate degrees of skin penetration. These images underwent interactive segmentation and image processing in addition to statistical quantitative analyses of calculated image parameters including the mean, integrated density, skewness, kurtosis, and area fraction. In images from both groups, the distribution area and intensity of fluorescent silica gradually increased in proportion to time. Since statistical significance was achieved after 2 days in the negative charge group and after 4 days in the positive charge group, there is a periodic difference. Furthermore, the quantity of silica per unit area showed a dramatic change after 6 days in the negative charge group. Although this quantitative result is identical to results obtained by qualitative assessment, it is meaningful in that it was proven by statistical analysis with quantitation by using image processing. The present study suggests that the surface charge of SNPs could play an important role in the percutaneous absorption of NPs. These findings can help achieve a better understanding of the percutaneous transport of NPs. In addition, these results provide important guidance for the design of NPs for biomedical applications.

A Quantitative Comparative Study of Blended and Traditional Models in the Secondary Advanced Placement Statistics Classroom

ERIC Educational Resources Information Center

Owens, Susan T.

2017-01-01

Technology is becoming an integral tool in the classroom and can make a positive impact on how the students learn. This quantitative comparative research study examined gender-based differences among secondary Advanced Placement (AP) Statistic students comparing Educational Testing Service (ETS) College Board AP Statistic examination scores…

Sociological Paradoxes and Graduate Statistics Classes. A Response to "The Sociology of Teaching Graduate Statistics"

ERIC Educational Resources Information Center

Hardy, Melissa

2005-01-01

This article presents a response to Timothy Patrick Moran's article "The Sociology of Teaching Graduate Statistics." In his essay, Moran argues that exciting developments in techniques of quantitative analysis are currently coupled with a much less exciting formulaic approach to teaching sociology graduate students about quantitative analysis. The…

Early Assessment of Treatment Responses During Radiation Therapy for Lung Cancer Using Quantitative Analysis of Daily Computed Tomography

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

Paul, Jijo; Yang, Cungeng; Wu, Hui

Purpose: To investigate early tumor and normal tissue responses during the course of radiation therapy (RT) for lung cancer using quantitative analysis of daily computed tomography (CT) scans. Methods and Materials: Daily diagnostic-quality CT scans acquired using CT-on-rails during CT-guided RT for 20 lung cancer patients were quantitatively analyzed. On each daily CT set, the contours of the gross tumor volume (GTV) and lungs were generated and the radiation dose delivered was reconstructed. The changes in CT image intensity (Hounsfield unit [HU]) features in the GTV and the multiple normal lung tissue shells around the GTV were extracted from themore » daily CT scans. The associations between the changes in the mean HUs, GTV, accumulated dose during RT delivery, and patient survival rate were analyzed. Results: During the RT course, radiation can induce substantial changes in the HU histogram features on the daily CT scans, with reductions in the GTV mean HUs (dH) observed in the range of 11 to 48 HU (median 30). The dH is statistically related to the accumulated GTV dose (R{sup 2} > 0.99) and correlates weakly with the change in GTV (R{sup 2} = 0.3481). Statistically significant increases in patient survival rates (P=.038) were observed for patients with a higher dH in the GTV. In the normal lung, the 4 regions proximal to the GTV showed statistically significant (P<.001) HU reductions from the first to last fraction. Conclusion: Quantitative analysis of the daily CT scans indicated that the mean HUs in lung tumor and surrounding normal tissue were reduced during RT delivery. This reduction was observed in the early phase of the treatment, is patient specific, and correlated with the delivered dose. A larger HU reduction in the GTV correlated significantly with greater patient survival. The changes in daily CT features, such as the mean HU, can be used for early assessment of the radiation response during RT delivery for lung cancer.« less

Early Assessment of Treatment Responses During Radiation Therapy for Lung Cancer Using Quantitative Analysis of Daily Computed Tomography.

PubMed

Paul, Jijo; Yang, Cungeng; Wu, Hui; Tai, An; Dalah, Entesar; Zheng, Cheng; Johnstone, Candice; Kong, Feng-Ming; Gore, Elizabeth; Li, X Allen

2017-06-01

To investigate early tumor and normal tissue responses during the course of radiation therapy (RT) for lung cancer using quantitative analysis of daily computed tomography (CT) scans. Daily diagnostic-quality CT scans acquired using CT-on-rails during CT-guided RT for 20 lung cancer patients were quantitatively analyzed. On each daily CT set, the contours of the gross tumor volume (GTV) and lungs were generated and the radiation dose delivered was reconstructed. The changes in CT image intensity (Hounsfield unit [HU]) features in the GTV and the multiple normal lung tissue shells around the GTV were extracted from the daily CT scans. The associations between the changes in the mean HUs, GTV, accumulated dose during RT delivery, and patient survival rate were analyzed. During the RT course, radiation can induce substantial changes in the HU histogram features on the daily CT scans, with reductions in the GTV mean HUs (dH) observed in the range of 11 to 48 HU (median 30). The dH is statistically related to the accumulated GTV dose (R 2  > 0.99) and correlates weakly with the change in GTV (R 2  = 0.3481). Statistically significant increases in patient survival rates (P=.038) were observed for patients with a higher dH in the GTV. In the normal lung, the 4 regions proximal to the GTV showed statistically significant (P<.001) HU reductions from the first to last fraction. Quantitative analysis of the daily CT scans indicated that the mean HUs in lung tumor and surrounding normal tissue were reduced during RT delivery. This reduction was observed in the early phase of the treatment, is patient specific, and correlated with the delivered dose. A larger HU reduction in the GTV correlated significantly with greater patient survival. The changes in daily CT features, such as the mean HU, can be used for early assessment of the radiation response during RT delivery for lung cancer. Copyright © 2017 Elsevier Inc. All rights reserved.

Jordanian twelfth-grade science teachers' self-reported usage of science and engineering practices in the next generation science standards

NASA Astrophysics Data System (ADS)

Malkawi, Amal Reda; Rababah, Ebtesam Qassim

2018-06-01

This study investigated the degree that Science and Engineering Practices (SEPs) criteria from the Next Generation Science Standards (NGSS) were included in self-reported teaching practices of twelfth-grade science teachers in Jordan. This study sampled (n = 315) science teachers recruited from eight different public school directorates. The sample was surveyed using an instrument adapted from Kawasaki (2015). Results found that Jordanian science teachers incorporate (SEPs) in their classroom teaching at only a moderate level. SEPs applied most frequently included 'using the diagram, table or graphic through instructions to clarify the subject of a new science,' and to 'discuss with the students how to interpret the quantitative data from the experiment or investigation'. The practice with the lowest frequency was 'teach a lesson on interpreting statistics or quantitative data,' which was moderately applied. No statistically significant differences at (α = 0.05) were found among these Jordanian science teachers' self-estimations of (SEP) application into their own teaching according to the study's demographic variables (specialisation, educational qualification, teaching experience). However, a statistically significant difference at (α = 0.05) was found among Jordanian high school science teachers' practice means based on gender, with female teachers using SEPs at a higher rate than male teachers.

Evaluation of the remineralization capacity of CPP-ACP containing fluoride varnish by different quantitative methods

PubMed Central

SAVAS, Selcuk; KAVRÌK, Fevzi; KUCUKYÌLMAZ, Ebru

2016-01-01

ABSTRACT Objective The aim of this study was to evaluate the efficacy of CPP-ACP containing fluoride varnish for remineralizing white spot lesions (WSLs) with four different quantitative methods. Material and Methods Four windows (3x3 mm) were created on the enamel surfaces of bovine incisor teeth. A control window was covered with nail varnish, and WSLs were created on the other windows (after demineralization, first week and fourth week) in acidified gel system. The test material (MI Varnish) was applied on the demineralized areas, and the treated enamel samples were stored in artificial saliva. At the fourth week, the enamel surfaces were tested by surface microhardness (SMH), quantitative light-induced fluorescence-digital (QLF-D), energy-dispersive spectroscopy (EDS) and laser fluorescence (LF pen). The data were statistically analyzed (α=0.05). Results While the LF pen measurements showed significant differences at baseline, after demineralization, and after the one-week remineralization period (p<0.05), the difference between the 1- and 4-week was not significant (p>0.05). With regards to the SMH and QLF-D analyses, statistically significant differences were found among all the phases (p<0.05). After the 1- and 4-week treatment periods, the calcium (Ca) and phosphate (P) concentrations and Ca/P ratio were higher compared to those of the demineralization surfaces (p<0.05). Conclusion CPP-ACP containing fluoride varnish provides remineralization of WSLs after a single application and seems suitable for clinical use. PMID:27383699

Radiochromium (chromium-51) evaluation of gastrointestinal blood loss associated with placebo, aspirin, and nabumetone

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

Lussier, A.; LeBel, E.

Gastrointestinal blood loss is one of the most serious clinical events induced by drugs. To date, almost no nonsteroidal anti-inflammatory drug has been shown to be devoid of that side effect in a strictly controlled study. The objective of this study was to assess quantitatively, by use of radioactive chromium (chromium-51)-labeled red blood cells, gastrointestinal blood loss associated with nabumetone (1000 mg daily), aspirin (3.6 g daily), and placebo. A total of 37 normal subjects, divided among the three treatment groups and a fourth group that received no treatment, were assessed clinically and quantitatively for gastrointestinal blood loss over amore » period of 28 days of active treatment. The results with chromium-51, analyzed on a logarithmic scale, revealed no statistically significant differences between the nabumetone, placebo, and control groups. Gastrointestinal blood loss in the aspirin group, however, was elevated when compared with all other groups at a high level of statistical significance (p less than 0.001). It is concluded that, under conditions in which aspirin causes substantial gastrointestinal microbleeding, nabumetone is not significantly different from placebo.« less

Comparative study of contrast-enhanced ultrasound qualitative and quantitative analysis for identifying benign and malignant breast tumor lumps.

PubMed

Liu, Jian; Gao, Yun-Hua; Li, Ding-Dong; Gao, Yan-Chun; Hou, Ling-Mi; Xie, Ting

2014-01-01

To compare the value of contrast-enhanced ultrasound (CEUS) qualitative and quantitative analysis in the identification of breast tumor lumps. Qualitative and quantitative indicators of CEUS for 73 cases of breast tumor lumps were retrospectively analyzed by univariate and multivariate approaches. Logistic regression was applied and ROC curves were drawn for evaluation and comparison. The CEUS qualitative indicator-generated regression equation contained three indicators, namely enhanced homogeneity, diameter line expansion and peak intensity grading, which demonstrated prediction accuracy for benign and malignant breast tumor lumps of 91.8%; the quantitative indicator-generated regression equation only contained one indicator, namely the relative peak intensity, and its prediction accuracy was 61.5%. The corresponding areas under the ROC curve for qualitative and quantitative analyses were 91.3% and 75.7%, respectively, which exhibited a statistically significant difference by the Z test (P<0.05). The ability of CEUS qualitative analysis to identify breast tumor lumps is better than with quantitative analysis.

Reporting of Numerical and Statistical Differences in Abstracts

PubMed Central

Dryver, Eric; Hux, Janet E

2002-01-01

OBJECTIVE The reporting of relative risk reductions (RRRs) or absolute risk reductions (ARRs) to quantify binary outcomes in trials engenders differing perceptions of therapeutic efficacy, and the merits of P values versus confidence intervals (CIs) are also controversial. We describe the manner in which numerical and statistical difference in treatment outcomes is presented in published abstracts. DESIGN A descriptive study of abstracts published in 1986 and 1996 in 8 general medical and specialty journals. Inclusion criteria: controlled, intervention trials with a binary primary or secondary outcome. Seven items were recorded: raw data (outcomes for each treatment arm), measure of relative difference (e.g., RRR), ARR, number needed to treat, P value, CI, and verbal statement of statistical significance. The prevalence of these items was compared between journals and across time. RESULTS Of 5,293 abstracts, 300 met the inclusion criteria. In 1986, 60% of abstracts did not provide both the raw data and a corresponding P value or CI, while 28% failed to do so in 1Dr. Hux is a Career Scientist of the Ontario Ministry of Health and receives salary support from the Institute for Clinical Evaluative Sciences in Ontario.996 (P < .001; RRR of 53%; ARR of 32%; CI for ARR 21% to 43%). The variability between journals was highly significant (P < .001). In 1986, 100% of abstracts lacked a measure of absolute difference while 88% of 1996 abstracts did so (P < .001). In 1986, 98% of abstracts lacked a CI while 65% of 1996 abstracts did so (P < .001). CONCLUSIONS The provision of quantitative outcome and statistical quantitative information has significantly increased between 1986 and 1996. However, further progress can be made to make abstracts more informative. PMID:11929506

Immunohistochemical evaluation of inducible nitric oxide synthase in the epithelial lining of odontogenic cysts: A qualitative and quantitative analysis.

PubMed

Akshatha, B K; Karuppiah, Karpagaselvi; Manjunath, G S; Kumarswamy, Jayalakshmi; Papaiah, Lokesh; Rao, Jyothi

2017-01-01

The three common odontogenic cysts include radicular cysts (RCs), dentigerous cysts (DCs), and odontogenic keratocysts (OKCs). Among these 3 cysts, OKC is recently been classified as benign keratocystic odontogenic tumor attributing to its aggressive behavior, recurrence rate, and malignant potential. The present study involved qualitative and quantitative analysis of inducible nitric oxide synthase (iNOS) expression in epithelial lining of RCs, DCs, and OKCs, compare iNOS expression in epithelial linings of all the 3 cysts and determined overexpression of iNOS in OKCs which might contribute to its aggressive behavior and malignant potential. The present study is to investigate the role of iNOS in the pathogenesis of OKCs, DCs, and RCs by evaluating the iNOS expression in the epithelial lining of these cysts. Analysis of iNOS expression in epithelial lining cells of 20 RCs, 20 DCs, and 20 OKCs using immunohistochemistry done. The percentage of positive cells and intensity of stain was assessed and compared among all the 3 cysts using contingency coefficient. Kappa statistics for the two observers were computed for finding interobserver agreement. The percentage of iNOS-positive cells was found to be remarkably high in OKCs (12/20) -57.1% as compared to RCs (6/20) - 28.6% and DCs (3/20) - 14.3%. The interobserver agreement for iNOS-positive percentage cells was arrived with kappa values with OKCs → Statistically significant ( P > 0.000), RCs → statistically significant ( P > 0.001) with no significant values for DCs. No statistical difference exists among 3 study samples in regard to the intensity of staining with iNOS. Increased iNOS expression in OKCs may contribute to bone resorption and accumulation of wild-type p53, hence, making OKCs more aggressive.

Reporting of numerical and statistical differences in abstracts: improving but not optimal.

PubMed

Dryver, Eric; Hux, Janet E

2002-03-01

The reporting of relative risk reductions (RRRs) or absolute risk reductions (ARRs) to quantify binary outcomes in trials engenders differing perceptions of therapeutic efficacy, and the merits of P values versus confidence intervals (CIs) are also controversial. We describe the manner in which numerical and statistical difference in treatment outcomes is presented in published abstracts. A descriptive study of abstracts published in 1986 and 1996 in 8 general medical and specialty journals. controlled, intervention trials with a binary primary or secondary outcome. Seven items were recorded: raw data (outcomes for each treatment arm), measure of relative difference (e.g., RRR), ARR, number needed to treat, P value, CI, and verbal statement of statistical significance. The prevalence of these items was compared between journals and across time. Of 5,293 abstracts, 300 met the inclusion criteria. In 1986, 60% of abstracts did not provide both the raw data and a corresponding P value or CI, while 28% failed to do so in 1Dr. Hux is a Career Scientist of the Ontario Ministry of Health and receives salary support from the Institute for Clinical Evaluative Sciences in Ontario.996 ( P <.001; RRR of 53%; ARR of 32%; CI for ARR 21% to 43%). The variability between journals was highly significant ( P <.001). In 1986, 100% of abstracts lacked a measure of absolute difference while 88% of 1996 abstracts did so ( P <.001). In 1986, 98% of abstracts lacked a CI while 65% of 1996 abstracts did so ( P <.001). The provision of quantitative outcome and statistical quantitative information has significantly increased between 1986 and 1996. However, further progress can be made to make abstracts more informative.

Quantitative analysis of Porcine Reproductive and Respiratory Syndrome (PRRS) viremia profiles from experimental infection: a statistical modelling approach

USDA-ARS?s Scientific Manuscript database

Porcine reproductive and respiratory syndrome (PRRS) is the most economically significant viral disease facing the global swine industry. Viremia profiles of PRRS virus challenged pigs reflect the severity and progression of the infection within the host and provide crucial information for subsequen...

Multimedia Instructional Tools and Student Learning in an Integrated Business Applications Course

ERIC Educational Resources Information Center

Wells, Sandra H.

2018-01-01

The purpose of this quantitative descriptive comparative study was to investigate and explore the usage of multimedia instructional tools (MMITs) in an integrated business applications course to determine if there was a statistically significant difference in the gain scores between the pretest and posttest scores of high school students who used…

Quantitative Analysis of Standardized Dress Code and Minority Academic Achievement

ERIC Educational Resources Information Center

Proctor, J. R.

2013-01-01

This study was designed to investigate if a statistically significant variance exists in African American and Hispanic students' attendance and Texas Assessment of Knowledge and Skills test scores in mathematics before and after the implementation of a standardized dress code. For almost two decades supporters and opponents of public school…

Improving Research Clarity and Usefulness with Effect Size Indices as Supplements to Statistical Significance Tests.

ERIC Educational Resources Information Center

Thompson, Bruce

1999-01-01

A study examined effect-size reporting in 23 quantitative articles reported in "Exceptional Children". Findings reveal that effect sizes are rarely being reported, although exemplary reporting practices were also noted. Reasons why encouragement by the American Psychological Association to report effect size has been ineffective are…

Parents' Attitudes toward Mathematics and the Influence on Their Students' Attitudes toward Mathematics: A Quantitative Study

ERIC Educational Resources Information Center

Mohr-Schroeder, Margaret J.; Jackson, Christa; Cavalcanti, Maureen; Jong, Cindy; Schroeder, D. Craig; Speler, Lydia G.

2017-01-01

The purpose of this study was to investigate parents' attitudes toward mathematics, their students' attitude toward mathematics, and the influence of the parents' attitude on the students' attitude toward mathematics. Data analyses revealed statistically significant positive correlations between parents' and students' attitudes toward mathematics.…

Automated Quantitative Analysis of Retinal Microvasculature in Normal Eyes on Optical Coherence Tomography Angiography.

PubMed

Lupidi, Marco; Coscas, Florence; Cagini, Carlo; Fiore, Tito; Spaccini, Elisa; Fruttini, Daniela; Coscas, Gabriel

2016-09-01

To describe a new automated quantitative technique for displaying and analyzing macular vascular perfusion using optical coherence tomography angiography (OCT-A) and to determine a normative data set, which might be used as reference in identifying progressive changes due to different retinal vascular diseases. Reliability study. A retrospective review of 47 eyes of 47 consecutive healthy subjects imaged with a spectral-domain OCT-A device was performed in a single institution. Full-spectrum amplitude-decorrelation angiography generated OCT angiograms of the retinal superficial and deep capillary plexuses. A fully automated custom-built software was used to provide quantitative data on the foveal avascular zone (FAZ) features and the total vascular and avascular surfaces. A comparative analysis between central macular thickness (and volume) and FAZ metrics was performed. Repeatability and reproducibility were also assessed in order to establish the feasibility and reliability of the method. The comparative analysis between the superficial capillary plexus and the deep capillary plexus revealed a statistically significant difference (P < .05) in terms of FAZ perimeter, surface, and major axis and a not statistically significant difference (P > .05) when considering total vascular and avascular surfaces. A linear correlation was demonstrated between central macular thickness (and volume) and the FAZ surface. Coefficients of repeatability and reproducibility were less than 0.4, thus demonstrating high intraobserver repeatability and interobserver reproducibility for all the examined data. A quantitative approach on retinal vascular perfusion, which is visible on Spectralis OCT angiography, may offer an objective and reliable method for monitoring disease progression in several retinal vascular diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

The impact of a scheduling change on ninth grade high school performance on biology benchmark exams and the California Standards Test

NASA Astrophysics Data System (ADS)

Leonardi, Marcelo

The primary purpose of this study was to examine the impact of a scheduling change from a trimester 4x4 block schedule to a modified hybrid schedule on student achievement in ninth grade biology courses. This study examined the impact of the scheduling change on student achievement through teacher created benchmark assessments in Genetics, DNA, and Evolution and on the California Standardized Test in Biology. The secondary purpose of this study examined the ninth grade biology teacher perceptions of ninth grade biology student achievement. Using a mixed methods research approach, data was collected both quantitatively and qualitatively as aligned to research questions. Quantitative methods included gathering data from departmental benchmark exams and California Standardized Test in Biology and conducting multiple analysis of covariance and analysis of covariance to determine significance differences. Qualitative methods include journal entries questions and focus group interviews. The results revealed a statistically significant increase in scores on both the DNA and Evolution benchmark exams. DNA and Evolution benchmark exams showed significant improvements from a change in scheduling format. The scheduling change was responsible for 1.5% of the increase in DNA benchmark scores and 2% of the increase in Evolution benchmark scores. The results revealed a statistically significant decrease in scores on the Genetics Benchmark exam as a result of the scheduling change. The scheduling change was responsible for 1% of the decrease in Genetics benchmark scores. The results also revealed a statistically significant increase in scores on the CST Biology exam. The scheduling change was responsible for .7% of the increase in CST Biology scores. Results of the focus group discussions indicated that all teachers preferred the modified hybrid schedule over the trimester schedule and that it improved student achievement.

Diagnostic value of (99m)Tc-3PRGD2 scintimammography for differentiation of malignant from benign breast lesions: Comparison of visual and semi-quantitative analysis.

PubMed

Chen, Qianqian; Xie, Qian; Zhao, Min; Chen, Bin; Gao, Shi; Zhang, Haishan; Xing, Hua; Ma, Qingjie

2015-01-01

To compare the diagnostic value of visual and semi-quantitative analysis of technetium-99m-poly-ethylene glycol, 4-arginine-glycine-aspartic acid ((99m)Tc-3PRGD2) scintimammography (SMG) for better differentiation of benign from malignant breast masses, and also investigate the incremental role of semi-quantitative index of SMG. A total of 72 patients with breast lesions were included in the study. Technetium-99m-3PRGD2 SMG was performed with single photon emission computed tomography (SPET) at 60 min after intravenous injection of 749 ± 86MBq of the radiotracer. Images were evaluated by visual interpretation and semi-quantitative indices of tumor to non-tumor (T/N) ratios, which were compared with pathology results. Receiver operating characteristics (ROC) curve analyses were performed to determine the optimal visual grade, to calculate cut-off values of semi-quantitative indices, and to compare visual and semi-quantitative diagnostic values. Among the 72 patients, 89 lesions were confirmed by histopathology after fine needle aspiration biopsy or surgery, 48 malignant and 41 benign lesions. The mean T/N ratio of (99m)Tc-3PRGD2 SMG in malignant lesions was significantly higher than that in benign lesions (P<0.05). When grade 2 of the disease was used as cut-off value for the detection of primary breast cancer, the sensitivity, specificity and accuracy were 81.3%, 70.7%, and 76.4%, respectively. When a T/N ratio of 2.01 was used as cut-off value, the sensitivity, specificity and accuracy were 79.2%, 75.6%, and 77.5%, respectively. According to ROC analysis, the area under the curve for semi-quantitative analysis was higher than that for visual analysis, but the statistical difference was not significant (P=0.372). Compared with visual analysis or semi-quantitative analysis alone, the sensitivity, specificity and accuracy of visual analysis combined with semi-quantitative analysis in diagnosing primary breast cancer were higher, being: 87.5%, 82.9%, and 85.4%, respectively. The area under the curve was 0.891. Results of the present study suggest that the semi-quantitative and visual analysis statistically showed similar results. The semi-quantitative analysis provided incremental value additive to visual analysis of (99m)Tc-3PRGD2 SMG for the detection of breast cancer. It seems from our results that, when the tumor was located in the medial part of the breast, the semi-quantitative analysis gave better diagnostic results.

Making Social Work Count: A Curriculum Innovation to Teach Quantitative Research Methods and Statistical Analysis to Undergraduate Social Work Students in the United Kingdom

ERIC Educational Resources Information Center

Teater, Barbra; Roy, Jessica; Carpenter, John; Forrester, Donald; Devaney, John; Scourfield, Jonathan

2017-01-01

Students in the United Kingdom (UK) are found to lack knowledge and skills in quantitative research methods. To address this gap, a quantitative research method and statistical analysis curriculum comprising 10 individual lessons was developed, piloted, and evaluated at two universities The evaluation found that BSW students' (N = 81)…

The skeletal maturation status estimated by statistical shape analysis: axial images of Japanese cervical vertebra.

PubMed

Shin, S M; Kim, Y-I; Choi, Y-S; Yamaguchi, T; Maki, K; Cho, B-H; Park, S-B

2015-01-01

To evaluate axial cervical vertebral (ACV) shape quantitatively and to build a prediction model for skeletal maturation level using statistical shape analysis for Japanese individuals. The sample included 24 female and 19 male patients with hand-wrist radiographs and CBCT images. Through generalized Procrustes analysis and principal components (PCs) analysis, the meaningful PCs were extracted from each ACV shape and analysed for the estimation regression model. Each ACV shape had meaningful PCs, except for the second axial cervical vertebra. Based on these models, the smallest prediction intervals (PIs) were from the combination of the shape space PCs, age and gender. Overall, the PIs of the male group were smaller than those of the female group. There was no significant correlation between centroid size as a size factor and skeletal maturation level. Our findings suggest that the ACV maturation method, which was applied by statistical shape analysis, could confirm information about skeletal maturation in Japanese individuals as an available quantifier of skeletal maturation and could be as useful a quantitative method as the skeletal maturation index.

The skeletal maturation status estimated by statistical shape analysis: axial images of Japanese cervical vertebra

PubMed Central

Shin, S M; Choi, Y-S; Yamaguchi, T; Maki, K; Cho, B-H; Park, S-B

2015-01-01

Objectives: To evaluate axial cervical vertebral (ACV) shape quantitatively and to build a prediction model for skeletal maturation level using statistical shape analysis for Japanese individuals. Methods: The sample included 24 female and 19 male patients with hand–wrist radiographs and CBCT images. Through generalized Procrustes analysis and principal components (PCs) analysis, the meaningful PCs were extracted from each ACV shape and analysed for the estimation regression model. Results: Each ACV shape had meaningful PCs, except for the second axial cervical vertebra. Based on these models, the smallest prediction intervals (PIs) were from the combination of the shape space PCs, age and gender. Overall, the PIs of the male group were smaller than those of the female group. There was no significant correlation between centroid size as a size factor and skeletal maturation level. Conclusions: Our findings suggest that the ACV maturation method, which was applied by statistical shape analysis, could confirm information about skeletal maturation in Japanese individuals as an available quantifier of skeletal maturation and could be as useful a quantitative method as the skeletal maturation index. PMID:25411713

Quantitative analysis of diffusion tensor imaging (DTI) using statistical parametric mapping (SPM) for brain disorders

NASA Astrophysics Data System (ADS)

Lee, Jae-Seung; Im, In-Chul; Kang, Su-Man; Goo, Eun-Hoe; Kwak, Byung-Joon

2013-07-01

This study aimed to quantitatively analyze data from diffusion tensor imaging (DTI) using statistical parametric mapping (SPM) in patients with brain disorders and to assess its potential utility for analyzing brain function. DTI was obtained by performing 3.0-T magnetic resonance imaging for patients with Alzheimer's disease (AD) and vascular dementia (VD), and the data were analyzed using Matlab-based SPM software. The two-sample t-test was used for error analysis of the location of the activated pixels. We compared regions of white matter where the fractional anisotropy (FA) values were low and the apparent diffusion coefficients (ADCs) were increased. In the AD group, the FA values were low in the right superior temporal gyrus, right inferior temporal gyrus, right sub-lobar insula, and right occipital lingual gyrus whereas the ADCs were significantly increased in the right inferior frontal gyrus and right middle frontal gyrus. In the VD group, the FA values were low in the right superior temporal gyrus, right inferior temporal gyrus, right limbic cingulate gyrus, and right sub-lobar caudate tail whereas the ADCs were significantly increased in the left lateral globus pallidus and left medial globus pallidus. In conclusion by using DTI and SPM analysis, we were able to not only determine the structural state of the regions affected by brain disorders but also quantitatively analyze and assess brain function.

Communication: Dominance of extreme statistics in a prototype many-body Brownian ratchet.

PubMed

Hohlfeld, Evan; Geissler, Phillip L

2014-10-28

Many forms of cell motility rely on Brownian ratchet mechanisms that involve multiple stochastic processes. We present a computational and theoretical study of the nonequilibrium statistical dynamics of such a many-body ratchet, in the specific form of a growing polymer gel that pushes a diffusing obstacle. We find that oft-neglected correlations among constituent filaments impact steady-state kinetics and significantly deplete the gel's density within molecular distances of its leading edge. These behaviors are captured quantitatively by a self-consistent theory for extreme fluctuations in filaments' spatial distribution.

LOD significance thresholds for QTL analysis in experimental populations of diploid species

PubMed

Van Ooijen JW

1999-11-01

Linkage analysis with molecular genetic markers is a very powerful tool in the biological research of quantitative traits. The lack of an easy way to know what areas of the genome can be designated as statistically significant for containing a gene affecting the quantitative trait of interest hampers the important prediction of the rate of false positives. In this paper four tables, obtained by large-scale simulations, are presented that can be used with a simple formula to get the false-positives rate for analyses of the standard types of experimental populations with diploid species with any size of genome. A new definition of the term 'suggestive linkage' is proposed that allows a more objective comparison of results across species.

Immunohistochemical evaluation of inducible nitric oxide synthase in the epithelial lining of odontogenic cysts: A qualitative and quantitative analysis

PubMed Central

Akshatha, B K; Karuppiah, Karpagaselvi; Manjunath, G S; Kumarswamy, Jayalakshmi; Papaiah, Lokesh; Rao, Jyothi

2017-01-01

Introduction: The three common odontogenic cysts include radicular cysts (RCs), dentigerous cysts (DCs), and odontogenic keratocysts (OKCs). Among these 3 cysts, OKC is recently been classified as benign keratocystic odontogenic tumor attributing to its aggressive behavior, recurrence rate, and malignant potential. The present study involved qualitative and quantitative analysis of inducible nitric oxide synthase (iNOS) expression in epithelial lining of RCs, DCs, and OKCs, compare iNOS expression in epithelial linings of all the 3 cysts and determined overexpression of iNOS in OKCs which might contribute to its aggressive behavior and malignant potential. Aims: The present study is to investigate the role of iNOS in the pathogenesis of OKCs, DCs, and RCs by evaluating the iNOS expression in the epithelial lining of these cysts. Subjects and Methods: Analysis of iNOS expression in epithelial lining cells of 20 RCs, 20 DCs, and 20 OKCs using immunohistochemistry done. Statistical Analysis Used: The percentage of positive cells and intensity of stain was assessed and compared among all the 3 cysts using contingency coefficient. Kappa statistics for the two observers were computed for finding interobserver agreement. Results: The percentage of iNOS-positive cells was found to be remarkably high in OKCs (12/20) –57.1% as compared to RCs (6/20) – 28.6% and DCs (3/20) – 14.3%. The interobserver agreement for iNOS-positive percentage cells was arrived with kappa values with OKCs → Statistically significant (P > 0.000), RCs → statistically significant (P > 0.001) with no significant values for DCs. No statistical difference exists among 3 study samples in regard to the intensity of staining with iNOS. Conclusions: Increased iNOS expression in OKCs may contribute to bone resorption and accumulation of wild-type p53, hence, making OKCs more aggressive. PMID:29391711

Relationship between increasing concentrations of two carcinogens and statistical image descriptors of foci morphology in the cell transformation assay.

PubMed

Callegaro, Giulia; Corvi, Raffaella; Salovaara, Susan; Urani, Chiara; Stefanini, Federico M

2017-06-01

Cell Transformation Assays (CTAs) have long been proposed for the identification of chemical carcinogenicity potential. The endpoint of these in vitro assays is represented by the phenotypic alterations in cultured cells, which are characterized by the change from the non-transformed to the transformed phenotype. Despite the wide fields of application and the numerous advantages of CTAs, their use in regulatory toxicology has been limited in part due to concerns about the subjective nature of visual scoring, i.e. the step in which transformed colonies or foci are evaluated through morphological features. An objective evaluation of morphological features has been previously obtained through automated digital processing of foci images to extract the value of three statistical image descriptors. In this study a further potential of the CTA using BALB/c 3T3 cells is addressed by analysing the effect of increasing concentrations of two known carcinogens, benzo[a]pyrene and NiCl 2 , with different modes of action on foci morphology. The main result of our quantitative evaluation shows that the concentration of the considered carcinogens has an effect on foci morphology that is statistically significant for the mean of two among the three selected descriptors. Statistical significance also corresponds to visual relevance. The statistical analysis of variations in foci morphology due to concentration allowed to quantify morphological changes that can be visually appreciated but not precisely determined. Therefore, it has the potential of providing new quantitative parameters in CTAs, and of exploiting all the information encoded in foci. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Genome-wide Association Study Identifies New Loci for Resistance to Leptosphaeria maculans in Canola

PubMed Central

Raman, Harsh; Raman, Rosy; Coombes, Neil; Song, Jie; Diffey, Simon; Kilian, Andrzej; Lindbeck, Kurt; Barbulescu, Denise M.; Batley, Jacqueline; Edwards, David; Salisbury, Phil A.; Marcroft, Steve

2016-01-01

Key message “We identified both quantitative and quantitative resistance loci to Leptosphaeria maculans, a fungal pathogen, causing blackleg disease in canola. Several genome-wide significant associations were detected at known and new loci for blackleg resistance. We further validated statistically significant associations in four genetic mapping populations, demonstrating that GWAS marker loci are indeed associated with resistance to L. maculans. One of the novel loci identified for the first time, Rlm12, conveys adult plant resistance in canola.” Blackleg, caused by Leptosphaeria maculans, is a significant disease which affects the sustainable production of canola (Brassica napus). This study reports a genome-wide association study based on 18,804 polymorphic SNPs to identify loci associated with qualitative and quantitative resistance to L. maculans. Genomic regions delimited with 694 significant SNP markers, that are associated with resistance evaluated using 12 single spore isolates and pathotypes from four canola stubble were identified. Several significant associations were detected at known disease resistance loci including in the vicinity of recently cloned Rlm2/LepR3 genes, and at new loci on chromosomes A01/C01, A02/C02, A03/C03, A05/C05, A06, A08, and A09. In addition, we validated statistically significant associations on A01, A07, and A10 in four genetic mapping populations, demonstrating that GWAS marker loci are indeed associated with resistance to L. maculans. One of the novel loci identified for the first time, Rlm12, conveys adult plant resistance and mapped within 13.2 kb from Arabidopsis R gene of TIR-NBS class. We showed that resistance loci are located in the vicinity of R genes of Arabidopsis thaliana and Brassica napus on the sequenced genome of B. napus cv. Darmor-bzh. Significantly associated SNP markers provide a valuable tool to enrich germplasm for favorable alleles in order to improve the level of resistance to L. maculans in canola. PMID:27822217

A knowledge-based T2-statistic to perform pathway analysis for quantitative proteomic data

PubMed Central

Chen, Yi-Hau

2017-01-01

Approaches to identify significant pathways from high-throughput quantitative data have been developed in recent years. Still, the analysis of proteomic data stays difficult because of limited sample size. This limitation also leads to the practice of using a competitive null as common approach; which fundamentally implies genes or proteins as independent units. The independent assumption ignores the associations among biomolecules with similar functions or cellular localization, as well as the interactions among them manifested as changes in expression ratios. Consequently, these methods often underestimate the associations among biomolecules and cause false positives in practice. Some studies incorporate the sample covariance matrix into the calculation to address this issue. However, sample covariance may not be a precise estimation if the sample size is very limited, which is usually the case for the data produced by mass spectrometry. In this study, we introduce a multivariate test under a self-contained null to perform pathway analysis for quantitative proteomic data. The covariance matrix used in the test statistic is constructed by the confidence scores retrieved from the STRING database or the HitPredict database. We also design an integrating procedure to retain pathways of sufficient evidence as a pathway group. The performance of the proposed T2-statistic is demonstrated using five published experimental datasets: the T-cell activation, the cAMP/PKA signaling, the myoblast differentiation, and the effect of dasatinib on the BCR-ABL pathway are proteomic datasets produced by mass spectrometry; and the protective effect of myocilin via the MAPK signaling pathway is a gene expression dataset of limited sample size. Compared with other popular statistics, the proposed T2-statistic yields more accurate descriptions in agreement with the discussion of the original publication. We implemented the T2-statistic into an R package T2GA, which is available at https://github.com/roqe/T2GA. PMID:28622336

A knowledge-based T2-statistic to perform pathway analysis for quantitative proteomic data.

PubMed

Lai, En-Yu; Chen, Yi-Hau; Wu, Kun-Pin

2017-06-01

Approaches to identify significant pathways from high-throughput quantitative data have been developed in recent years. Still, the analysis of proteomic data stays difficult because of limited sample size. This limitation also leads to the practice of using a competitive null as common approach; which fundamentally implies genes or proteins as independent units. The independent assumption ignores the associations among biomolecules with similar functions or cellular localization, as well as the interactions among them manifested as changes in expression ratios. Consequently, these methods often underestimate the associations among biomolecules and cause false positives in practice. Some studies incorporate the sample covariance matrix into the calculation to address this issue. However, sample covariance may not be a precise estimation if the sample size is very limited, which is usually the case for the data produced by mass spectrometry. In this study, we introduce a multivariate test under a self-contained null to perform pathway analysis for quantitative proteomic data. The covariance matrix used in the test statistic is constructed by the confidence scores retrieved from the STRING database or the HitPredict database. We also design an integrating procedure to retain pathways of sufficient evidence as a pathway group. The performance of the proposed T2-statistic is demonstrated using five published experimental datasets: the T-cell activation, the cAMP/PKA signaling, the myoblast differentiation, and the effect of dasatinib on the BCR-ABL pathway are proteomic datasets produced by mass spectrometry; and the protective effect of myocilin via the MAPK signaling pathway is a gene expression dataset of limited sample size. Compared with other popular statistics, the proposed T2-statistic yields more accurate descriptions in agreement with the discussion of the original publication. We implemented the T2-statistic into an R package T2GA, which is available at https://github.com/roqe/T2GA.

[A Review on the Use of Effect Size in Nursing Research].

PubMed

Kang, Hyuncheol; Yeon, Kyupil; Han, Sang Tae

2015-10-01

The purpose of this study was to introduce the main concepts of statistical testing and effect size and to provide researchers in nursing science with guidance on how to calculate the effect size for the statistical analysis methods mainly used in nursing. For t-test, analysis of variance, correlation analysis, regression analysis which are used frequently in nursing research, the generally accepted definitions of the effect size were explained. Some formulae for calculating the effect size are described with several examples in nursing research. Furthermore, the authors present the required minimum sample size for each example utilizing G*Power 3 software that is the most widely used program for calculating sample size. It is noted that statistical significance testing and effect size measurement serve different purposes, and the reliance on only one side may be misleading. Some practical guidelines are recommended for combining statistical significance testing and effect size measure in order to make more balanced decisions in quantitative analyses.

Environmental Health Practice: Statistically Based Performance Measurement

PubMed Central

Enander, Richard T.; Gagnon, Ronald N.; Hanumara, R. Choudary; Park, Eugene; Armstrong, Thomas; Gute, David M.

2007-01-01

Objectives. State environmental and health protection agencies have traditionally relied on a facility-by-facility inspection-enforcement paradigm to achieve compliance with government regulations. We evaluated the effectiveness of a new approach that uses a self-certification random sampling design. Methods. Comprehensive environmental and occupational health data from a 3-year statewide industry self-certification initiative were collected from representative automotive refinishing facilities located in Rhode Island. Statistical comparisons between baseline and postintervention data facilitated a quantitative evaluation of statewide performance. Results. The analysis of field data collected from 82 randomly selected automotive refinishing facilities showed statistically significant improvements (P<.05, Fisher exact test) in 4 major performance categories: occupational health and safety, air pollution control, hazardous waste management, and wastewater discharge. Statistical significance was also shown when a modified Bonferroni adjustment for multiple comparisons was performed. Conclusions. Our findings suggest that the new self-certification approach to environmental and worker protection is effective and can be used as an adjunct to further enhance state and federal enforcement programs. PMID:17267709

Leadership in nursing and patient satisfaction in hospital context.

PubMed

Nunes, Elisabete Maria Garcia Teles; Gaspar, Maria Filomena Mendes

2016-06-01

Objectives to know the quality of the leadership relationship from the perspective of a chief nurse and nurse, patient satisfaction, the relationship between the quality of the relationship perceived for both and patient satisfaction. Methods a quantitative, transverse and correlational approach. Non-probabilistic convenience sample consists of 15 chief nurses, 342 nurses, 273 patients. Data collected at the Central Lisbon Hospital Center, between January and March 2013, through the LMX-7, CLMX-7 and SUCEH21 scales. Statistical analysis was performed through SPSS ® Statistics 19. Results the chief nurse considers the quality of the leadership relationship good, the nurses consider it satisfactory, patients are considered to be satisfied with nursing care; there is a statistically significant correlation between the quality of the leadership relationship from the perspective of chief nurses and patient satisfaction, there is no statistically significant correlation between the quality of the leadership relationship in the nurse's perspective and satisfaction. Conclusion the chief nurse has a major role in patient satisfaction.

Atherosclerosis imaging using 3D black blood TSE SPACE vs 2D TSE

PubMed Central

Wong, Stephanie K; Mobolaji-Iawal, Motunrayo; Arama, Leron; Cambe, Joy; Biso, Sylvia; Alie, Nadia; Fayad, Zahi A; Mani, Venkatesh

2014-01-01

AIM: To compare 3D Black Blood turbo spin echo (TSE) sampling perfection with application-optimized contrast using different flip angle evolution (SPACE) vs 2D TSE in evaluating atherosclerotic plaques in multiple vascular territories. METHODS: The carotid, aortic, and femoral arterial walls of 16 patients at risk for cardiovascular or atherosclerotic disease were studied using both 3D black blood magnetic resonance imaging SPACE and conventional 2D multi-contrast TSE sequences using a consolidated imaging approach in the same imaging session. Qualitative and quantitative analyses were performed on the images. Agreement of morphometric measurements between the two imaging sequences was assessed using a two-sample t-test, calculation of the intra-class correlation coefficient and by the method of linear regression and Bland-Altman analyses. RESULTS: No statistically significant qualitative differences were found between the 3D SPACE and 2D TSE techniques for images of the carotids and aorta. For images of the femoral arteries, however, there were statistically significant differences in all four qualitative scores between the two techniques. Using the current approach, 3D SPACE is suboptimal for femoral imaging. However, this may be due to coils not being optimized for femoral imaging. Quantitatively, in our study, higher mean total vessel area measurements for the 3D SPACE technique across all three vascular beds were observed. No significant differences in lumen area for both the right and left carotids were observed between the two techniques. Overall, a significant-correlation existed between measures obtained between the two approaches. CONCLUSION: Qualitative and quantitative measurements between 3D SPACE and 2D TSE techniques are comparable. 3D-SPACE may be a feasible approach in the evaluation of cardiovascular patients. PMID:24876923

Quantitative structure-activity relationships by neural networks and inductive logic programming. II. The inhibition of dihydrofolate reductase by triazines

NASA Astrophysics Data System (ADS)

Hirst, Jonathan D.; King, Ross D.; Sternberg, Michael J. E.

1994-08-01

One of the largest available data sets for developing a quantitative structure-activity relationship (QSAR) — the inhibition of dihydrofolate reductase (DHFR) by 2,4-diamino-6,6-dimethyl-5-phenyl-dihydrotriazine derivatives — has been used for a sixfold cross-validation trial of neural networks, inductive logic programming (ILP) and linear regression. No statistically significant difference was found between the predictive capabilities of the methods. However, the representation of molecules by attributes, which is integral to the ILP approach, provides understandable rules about drug-receptor interactions.

Optimization of Statistical Methods Impact on Quantitative Proteomics Data.

PubMed

Pursiheimo, Anna; Vehmas, Anni P; Afzal, Saira; Suomi, Tomi; Chand, Thaman; Strauss, Leena; Poutanen, Matti; Rokka, Anne; Corthals, Garry L; Elo, Laura L

2015-10-02

As tools for quantitative label-free mass spectrometry (MS) rapidly develop, a consensus about the best practices is not apparent. In the work described here we compared popular statistical methods for detecting differential protein expression from quantitative MS data using both controlled experiments with known quantitative differences for specific proteins used as standards as well as "real" experiments where differences in protein abundance are not known a priori. Our results suggest that data-driven reproducibility-optimization can consistently produce reliable differential expression rankings for label-free proteome tools and are straightforward in their application.

Statistical Model to Analyze Quantitative Proteomics Data Obtained by 18O/16O Labeling and Linear Ion Trap Mass Spectrometry

PubMed Central

Jorge, Inmaculada; Navarro, Pedro; Martínez-Acedo, Pablo; Núñez, Estefanía; Serrano, Horacio; Alfranca, Arántzazu; Redondo, Juan Miguel; Vázquez, Jesús

2009-01-01

Statistical models for the analysis of protein expression changes by stable isotope labeling are still poorly developed, particularly for data obtained by 16O/18O labeling. Besides large scale test experiments to validate the null hypothesis are lacking. Although the study of mechanisms underlying biological actions promoted by vascular endothelial growth factor (VEGF) on endothelial cells is of considerable interest, quantitative proteomics studies on this subject are scarce and have been performed after exposing cells to the factor for long periods of time. In this work we present the largest quantitative proteomics study to date on the short term effects of VEGF on human umbilical vein endothelial cells by 18O/16O labeling. Current statistical models based on normality and variance homogeneity were found unsuitable to describe the null hypothesis in a large scale test experiment performed on these cells, producing false expression changes. A random effects model was developed including four different sources of variance at the spectrum-fitting, scan, peptide, and protein levels. With the new model the number of outliers at scan and peptide levels was negligible in three large scale experiments, and only one false protein expression change was observed in the test experiment among more than 1000 proteins. The new model allowed the detection of significant protein expression changes upon VEGF stimulation for 4 and 8 h. The consistency of the changes observed at 4 h was confirmed by a replica at a smaller scale and further validated by Western blot analysis of some proteins. Most of the observed changes have not been described previously and are consistent with a pattern of protein expression that dynamically changes over time following the evolution of the angiogenic response. With this statistical model the 18O labeling approach emerges as a very promising and robust alternative to perform quantitative proteomics studies at a depth of several thousand proteins. PMID:19181660

Measuring post-secondary stem majors' engagement in sustainability: The creation, assessment, and validation of an instrument for sustainability curricula evaluation

NASA Astrophysics Data System (ADS)

Little, David L., II

Ongoing changes in values, pedagogy, and curriculum concerning sustainability education necessitate that strong curricular elements are identified in sustainability education. However, quantitative research in sustainability education is largely undeveloped or relies on outdated instruments. In part, this is because no widespread quantitative instrument for measuring related educational outcomes has been developed for the field, though their development is pivotal for future efforts in sustainability education related to STEM majors. This research study details the creation, evaluation, and validation of an instrument -- the STEM Sustainability Engagement Instrument (STEMSEI) -- designed to measure sustainability engagement in post-secondary STEM majors. The study was conducted in three phases, using qualitative methods in phase 1, a concurrent mixed methods design in phase 2, and a sequential mixed methods design in phase 3. The STEMSEI was able to successfully predict statistically significant differences in the sample (n= 1017) that were predicted by prior research in environmental education. The STEMSEI also revealed statistically significant differences between STEM majors' sustainability engagement with a large effect size (.203 ≤ eta2 ≤ .211). As hypothesized, statistically significant differences were found on the environmental scales across gender and present religion. With respect to gender, self-perceived measures of emotional engagement with environmental sustainability was higher with females while males had higher measures in cognitive engagement with respect to knowing information related to environmental sustainability. With respect to present religion, self-perceived measures of general engagement and emotional engagement in environmental sustainability were higher for non-Christians as compared to Christians. On the economic scales, statistically significant differences were found across gender. Specifically, measures of males' self-perceived cognitive engagement in knowing information related to economic sustainability were greater than those of females. Future research should establish the generalizability of these results and further test the validity of the STEMSEI.

Effects of the Afterschool Program on Student Achievement of Students with Disabilities in a Rural Georgia Middle School

ERIC Educational Resources Information Center

Franklin, Constance

2017-01-01

The purpose of this quantitative nonexperimental causal comparative research study is to determine if there is a statistically significant difference in reading and math achievement as measured by the Georgia Criterion-Referenced Competency Test (CRCT) for sixth, seventh, and eighth grade students with disabilities (SWD) who attended the…

A Study Comparing Fifth Grade Student Achievement in Mathematics in Departmentalized and Non-Departmentalized Settings

ERIC Educational Resources Information Center

Nelson, Karen Ann

2014-01-01

The purpose of this quantitative, causal-comparative study was to examine the application of the teaching and learning theory of social constructivism in order to determine if mathematics instruction provided in a departmentalized classroom setting at the fifth grade level resulted in a statistically significant difference in student achievement…

The Mass Media: Aspen Institute Guide to Communication Industry Trends.

ERIC Educational Resources Information Center

Sterling, Christopher H.; Haight, Timothy R.

Intended to provide a single reference source for the most significant statistics describing communication industry trends in the United States since 1900, this book is a collection and assessment of the currently available quantitative descriptive information on mass media industries. The core of the book is its more than 300 tables of data on…

Preparing systems engineering and computing science students in disciplined methods, quantitative, and advanced statistical techniques to improve process performance

NASA Astrophysics Data System (ADS)

McCray, Wilmon Wil L., Jr.

The research was prompted by a need to conduct a study that assesses process improvement, quality management and analytical techniques taught to students in U.S. colleges and universities undergraduate and graduate systems engineering and the computing science discipline (e.g., software engineering, computer science, and information technology) degree programs during their academic training that can be applied to quantitatively manage processes for performance. Everyone involved in executing repeatable processes in the software and systems development lifecycle processes needs to become familiar with the concepts of quantitative management, statistical thinking, process improvement methods and how they relate to process-performance. Organizations are starting to embrace the de facto Software Engineering Institute (SEI) Capability Maturity Model Integration (CMMI RTM) Models as process improvement frameworks to improve business processes performance. High maturity process areas in the CMMI model imply the use of analytical, statistical, quantitative management techniques, and process performance modeling to identify and eliminate sources of variation, continually improve process-performance; reduce cost and predict future outcomes. The research study identifies and provides a detail discussion of the gap analysis findings of process improvement and quantitative analysis techniques taught in U.S. universities systems engineering and computing science degree programs, gaps that exist in the literature, and a comparison analysis which identifies the gaps that exist between the SEI's "healthy ingredients " of a process performance model and courses taught in U.S. universities degree program. The research also heightens awareness that academicians have conducted little research on applicable statistics and quantitative techniques that can be used to demonstrate high maturity as implied in the CMMI models. The research also includes a Monte Carlo simulation optimization model and dashboard that demonstrates the use of statistical methods, statistical process control, sensitivity analysis, quantitative and optimization techniques to establish a baseline and predict future customer satisfaction index scores (outcomes). The American Customer Satisfaction Index (ACSI) model and industry benchmarks were used as a framework for the simulation model.

Uncertainty of quantitative microbiological methods of pharmaceutical analysis.

PubMed

Gunar, O V; Sakhno, N G

2015-12-30

The total uncertainty of quantitative microbiological methods, used in pharmaceutical analysis, consists of several components. The analysis of the most important sources of the quantitative microbiological methods variability demonstrated no effect of culture media and plate-count techniques in the estimation of microbial count while the highly significant effect of other factors (type of microorganism, pharmaceutical product and individual reading and interpreting errors) was established. The most appropriate method of statistical analysis of such data was ANOVA which enabled not only the effect of individual factors to be estimated but also their interactions. Considering all the elements of uncertainty and combining them mathematically the combined relative uncertainty of the test results was estimated both for method of quantitative examination of non-sterile pharmaceuticals and microbial count technique without any product. These data did not exceed 35%, appropriated for a traditional plate count methods. Copyright © 2015 Elsevier B.V. All rights reserved.

A survey of work engagement and psychological capital levels.

PubMed

Bonner, Lynda

2016-08-11

To evaluate the relationship between work engagement and psychological capital (PsyCap) levels reported by registered nurses. PsyCap is a developable human resource. Research on PsyCap as an antecedent to work engagement in nurses is needed. A convenience sample of 137 registered nurses participated in this quantitative cross-sectional survey. Questionnaires measured self-reported levels of work engagement and psychological capital. Descriptive and inferential statistics were used for data analysis. There was a statistically significant correlation between work engagement and PsyCap scores (r=0.633, p<0.01). Nurses working at band 5 level reported statistically significantly lower PsyCap scores compared with nurses working at band 6 and 7 levels. Nurses reporting high levels of work engagement also reported high levels of PsyCap. Band 5 nurses might benefit most from interventions to increase their PsyCap. This study supports PsyCap as an antecedent to work engagement.

Teaching science in a technology rich environment: Probeware's effect on student attitude and achievement

NASA Astrophysics Data System (ADS)

Zelmanowicz, Marc

Purpose The use of technology in the science classroom has been a major part of the initiative toward increasing student attitude and achievement in Science, Technology, Education and Math [STEM] education in the United States. The purpose of this study was to determine the extent to which the use of probeware in a high school science living environment classroom impacts student attitude towards science and/or student achievement on standards-based assessments. This study sought to answer the following quantitative questions with a qualitative component: To what extent does the use of probeware in a high school level living environment course influence student attitudes toward science compared to students who are not using probeware? What is the impact, if any, on student achievement in a living environment course, as measured by New York State Living Environment Regents [NYSLER] exam grades, between students who use probeware and students who do not? Is there a significant difference between the two groups with regard to achieving mastery on the NYSLER exam? Sample The participants in the study were Living Environment students of a suburban high school outside of New York City. Methods The quasiexperimental study examined the effects of the replacement of traditional scientific equipment with probeware on student attitude and achievement in a living environment classroom. Student attitude was measured by the modified Attitude Toward Science Inventory [mATSI] and student achievement was measured by the New York State Living Environment Regents [NSLER] Exam. Descriptive statistics, ANCOVA and hierarchical regression analysis were conducted to answer the research questions in this study. A qualitative component was included to enhance the understanding of the quantitative analysis. Major Findings Through this study, results demonstrated a statistically significant impact of probeware on student attitude, but did not show a statistically significant impact of probeware on student achievement or achievement of mastery; The qualitative component confirmed that probeware positively impact student attitude and achievement. With regards to achievement, the qualitative interviews contradicted the quantitative analysis. Significance Results from this study add to the body of research that probeware can impact student attitude towards science education.

Less label, more free: approaches in label-free quantitative mass spectrometry.

PubMed

Neilson, Karlie A; Ali, Naveid A; Muralidharan, Sridevi; Mirzaei, Mehdi; Mariani, Michael; Assadourian, Gariné; Lee, Albert; van Sluyter, Steven C; Haynes, Paul A

2011-02-01

In this review we examine techniques, software, and statistical analyses used in label-free quantitative proteomics studies for area under the curve and spectral counting approaches. Recent advances in the field are discussed in an order that reflects a logical workflow design. Examples of studies that follow this design are presented to highlight the requirement for statistical assessment and further experiments to validate results from label-free quantitation. Limitations of label-free approaches are considered, label-free approaches are compared with labelling techniques, and forward-looking applications for label-free quantitative data are presented. We conclude that label-free quantitative proteomics is a reliable, versatile, and cost-effective alternative to labelled quantitation. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dynamical Systems Theory in Quantitative Psychology and Cognitive Science: A Fair Discrimination between Deterministic and Statistical Counterparts is Required.

PubMed

Gadomski, Adam; Ausloos, Marcel; Casey, Tahlia

2017-04-01

This article addresses a set of observations framed in both deterministic as well as statistical formal guidelines. It operates within the framework of nonlinear dynamical systems theory (NDS). It is argued that statistical approaches can manifest themselves ambiguously, creating practical discrepancies in psychological and cognitive data analyses both quantitatively and qualitatively. This is sometimes termed in literature as 'questionable research practices.' This communication points to the demand for a deeper awareness of the data 'initial conditions, allowing to focus on pertinent evolution constraints in such systems.' It also considers whether the exponential (Malthus-type) or the algebraic (Pareto-type) statistical distribution ought to be effectively considered in practical interpretations. The role of repetitive specific behaviors by patients seeking treatment is examined within the NDS frame. The significance of these behaviors, involving a certain memory effect seems crucial in determining a patient's progression or regression. With this perspective, it is discussed how a sensitively applied hazardous or triggering factor can be helpful for well-controlled psychological strategic treatments; those attributable to obsessive-compulsive disorders or self-injurious behaviors are recalled in particular. There are both inherent criticality- and complexity-exploiting (reduced-variance based) relations between a therapist and a patient that can be intrinsically included in NDS theory.

The Novel Quantitative Technique for Assessment of Gait Symmetry Using Advanced Statistical Learning Algorithm

PubMed Central

Wu, Jianning; Wu, Bin

2015-01-01

The accurate identification of gait asymmetry is very beneficial to the assessment of at-risk gait in the clinical applications. This paper investigated the application of classification method based on statistical learning algorithm to quantify gait symmetry based on the assumption that the degree of intrinsic change in dynamical system of gait is associated with the different statistical distributions between gait variables from left-right side of lower limbs; that is, the discrimination of small difference of similarity between lower limbs is considered the reorganization of their different probability distribution. The kinetic gait data of 60 participants were recorded using a strain gauge force platform during normal walking. The classification method is designed based on advanced statistical learning algorithm such as support vector machine algorithm for binary classification and is adopted to quantitatively evaluate gait symmetry. The experiment results showed that the proposed method could capture more intrinsic dynamic information hidden in gait variables and recognize the right-left gait patterns with superior generalization performance. Moreover, our proposed techniques could identify the small significant difference between lower limbs when compared to the traditional symmetry index method for gait. The proposed algorithm would become an effective tool for early identification of the elderly gait asymmetry in the clinical diagnosis. PMID:25705672

The novel quantitative technique for assessment of gait symmetry using advanced statistical learning algorithm.

PubMed

Wu, Jianning; Wu, Bin

2015-01-01

The accurate identification of gait asymmetry is very beneficial to the assessment of at-risk gait in the clinical applications. This paper investigated the application of classification method based on statistical learning algorithm to quantify gait symmetry based on the assumption that the degree of intrinsic change in dynamical system of gait is associated with the different statistical distributions between gait variables from left-right side of lower limbs; that is, the discrimination of small difference of similarity between lower limbs is considered the reorganization of their different probability distribution. The kinetic gait data of 60 participants were recorded using a strain gauge force platform during normal walking. The classification method is designed based on advanced statistical learning algorithm such as support vector machine algorithm for binary classification and is adopted to quantitatively evaluate gait symmetry. The experiment results showed that the proposed method could capture more intrinsic dynamic information hidden in gait variables and recognize the right-left gait patterns with superior generalization performance. Moreover, our proposed techniques could identify the small significant difference between lower limbs when compared to the traditional symmetry index method for gait. The proposed algorithm would become an effective tool for early identification of the elderly gait asymmetry in the clinical diagnosis.

Quantitative methods used in Australian health promotion research: a review of publications from 1992-2002.

PubMed

Smith, Ben J; Zehle, Katharina; Bauman, Adrian E; Chau, Josephine; Hawkshaw, Barbara; Frost, Steven; Thomas, Margaret

2006-04-01

This study examined the use of quantitative methods in Australian health promotion research in order to identify methodological trends and priorities for strengthening the evidence base for health promotion. Australian health promotion articles were identified by hand searching publications from 1992-2002 in six journals: Health Promotion Journal of Australia, Australian and New Zealand journal of Public Health, Health Promotion International, Health Education Research, Health Education and Behavior and the American Journal of Health Promotion. The study designs and statistical methods used in articles presenting quantitative research were recorded. 591 (57.7%) of the 1,025 articles used quantitative methods. Cross-sectional designs were used in the majority (54.3%) of studies with pre- and post-test (14.6%) and post-test only (9.5%) the next most common designs. Bivariate statistical methods were used in 45.9% of papers, multivariate methods in 27.1% and simple numbers and proportions in 25.4%. Few studies used higher-level statistical techniques. While most studies used quantitative methods, the majority were descriptive in nature. The study designs and statistical methods used provided limited scope for demonstrating intervention effects or understanding the determinants of change.

Calibration methods influence quantitative material decomposition in photon-counting spectral CT

NASA Astrophysics Data System (ADS)

Curtis, Tyler E.; Roeder, Ryan K.

2017-03-01

Photon-counting detectors and nanoparticle contrast agents can potentially enable molecular imaging and material decomposition in computed tomography (CT). Material decomposition has been investigated using both simulated and acquired data sets. However, the effect of calibration methods on material decomposition has not been systematically investigated. Therefore, the objective of this study was to investigate the influence of the range and number of contrast agent concentrations within a modular calibration phantom on quantitative material decomposition. A commerciallyavailable photon-counting spectral micro-CT (MARS Bioimaging) was used to acquire images with five energy bins selected to normalize photon counts and leverage the contrast agent k-edge. Material basis matrix values were determined using multiple linear regression models and material decomposition was performed using a maximum a posteriori estimator. The accuracy of quantitative material decomposition was evaluated by the root mean squared error (RMSE), specificity, sensitivity, and area under the curve (AUC). An increased maximum concentration (range) in the calibration significantly improved RMSE, specificity and AUC. The effects of an increased number of concentrations in the calibration were not statistically significant for the conditions in this study. The overall results demonstrated that the accuracy of quantitative material decomposition in spectral CT is significantly influenced by calibration methods, which must therefore be carefully considered for the intended diagnostic imaging application.

What Good Are Statistics that Don't Generalize?

ERIC Educational Resources Information Center

Shaffer, David Williamson; Serlin, Ronald C.

2004-01-01

Quantitative and qualitative inquiry are sometimes portrayed as distinct and incompatible paradigms for research in education. Approaches to combining qualitative and quantitative research typically "integrate" the two methods by letting them co-exist independently within a single research study. Here we describe intra-sample statistical analysis…

Contrast medium usage reduction in abdominal computed tomography by using high-iodinated concentration contrast medium

NASA Astrophysics Data System (ADS)

Suwannasri, A.; Kaewlai, R.; Asavaphatiboon, S.

2016-03-01

This study was to determine if administration of a low volume high-concentration iodinated contrast medium can preserve image quality in comparison with regular-concentration intravenous contrast medium in patient undergoing contrast-enhancement abdominal computed tomography (CT). Eighty-four patients were randomly divided into 3 groups of similar iodine delivery rate; A: 1.2 cc/kg of iomeprol-400, B: 1.0 cc/kg of iomeprol-400 and C: 1.5 cc/kg of ioversol-350. Contrast enhancement of the liver parenchyma, pancreas and aorta was quantitatively measured in Hounsfield units and qualitative assessed by a radiologist. T-test was used to evaluate contrast enhancement, and Chi-square test was used to evaluate qualitative image assessment, at significance level of 0.05 with 95% confidence intervals. There were no statistically significant differences in contrast enhancement of liver parenchyma and pancreas between group A and group C in both quantitative and qualitative analyses. Group C showed superior vascular enhancement to group A and B on quantitative analysis.

Occupational exposure decisions: can limited data interpretation training help improve accuracy?

PubMed

Logan, Perry; Ramachandran, Gurumurthy; Mulhausen, John; Hewett, Paul

2009-06-01

Accurate exposure assessments are critical for ensuring that potentially hazardous exposures are properly identified and controlled. The availability and accuracy of exposure assessments can determine whether resources are appropriately allocated to engineering and administrative controls, medical surveillance, personal protective equipment and other programs designed to protect workers. A desktop study was performed using videos, task information and sampling data to evaluate the accuracy and potential bias of participants' exposure judgments. Desktop exposure judgments were obtained from occupational hygienists for material handling jobs with small air sampling data sets (0-8 samples) and without the aid of computers. In addition, data interpretation tests (DITs) were administered to participants where they were asked to estimate the 95th percentile of an underlying log-normal exposure distribution from small data sets. Participants were presented with an exposure data interpretation or rule of thumb training which included a simple set of rules for estimating 95th percentiles for small data sets from a log-normal population. DIT was given to each participant before and after the rule of thumb training. Results of each DIT and qualitative and quantitative exposure judgments were compared with a reference judgment obtained through a Bayesian probabilistic analysis of the sampling data to investigate overall judgment accuracy and bias. There were a total of 4386 participant-task-chemical judgments for all data collections: 552 qualitative judgments made without sampling data and 3834 quantitative judgments with sampling data. The DITs and quantitative judgments were significantly better than random chance and much improved by the rule of thumb training. In addition, the rule of thumb training reduced the amount of bias in the DITs and quantitative judgments. The mean DIT % correct scores increased from 47 to 64% after the rule of thumb training (P < 0.001). The accuracy for quantitative desktop judgments increased from 43 to 63% correct after the rule of thumb training (P < 0.001). The rule of thumb training did not significantly impact accuracy for qualitative desktop judgments. The finding that even some simple statistical rules of thumb improve judgment accuracy significantly suggests that hygienists need to routinely use statistical tools while making exposure judgments using monitoring data.

Real-time quantitative polymerase chain reaction analysis of patients with refractory chronic periodontitis.

PubMed

Marconcini, Simone; Covani, Ugo; Barone, Antonio; Vittorio, Orazio; Curcio, Michele; Barbuti, Serena; Scatena, Fabrizio; Felli, Lamberto; Nicolini, Claudio

2011-07-01

Periodontitis is a complex multifactorial disease and is typically polygenic in origin. Genes play a fundamental part in each biologic process forming complex networks of interactions. However, only some genes have a high number of interactions with other genes in the network and may, therefore, be considered to play an important role. In a preliminary bioinformatic analysis, five genes that showed a higher number of interactions were identified and termed leader genes. In the present study, we use real-time quantitative polymerase chain reaction (PCR) technology to evaluate the expression levels of leader genes in the leukocytes of 10 patients with refractory chronic periodontitis and compare the expression levels with those of the same genes in 24 healthy patients. Blood was collected from 24 healthy human subjects and 10 patients with refractory chronic periodontitis and placed into heparinized blood collection tubes by personnel trained in phlebotomy using a sterile technique. Blood leukocyte cells were immediately lysed by using a kit for total RNA purification from human whole blood. Complementary DNA (cDNA) synthesis was obtained from total RNA and then real-time quantitative PCR was performed. PCR efficiencies were calculated with a relative standard curve derived from a five cDNA dilution series in triplicate that gave regression coefficients >0.98 and efficiencies >96%. The standard curves were obtained using glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and growth factor receptor binding protein 2 (GRB2), casitas B-lineage lymphoma (CBL), nuclear factor-KB1 (NFKB1), and REL-A (gene for transcription factor p65) gene primers and amplified with 1.6, 8, 40, 200, and 1,000 ng/μL total cDNA. Curves obtained for each sample showed a linear relationship between RNA concentrations and the cycle threshold value of real-time quantitative PCR for all genes. Data were expressed as mean ± SE (SEM). The groups were compared to the analysis of variance. A probability value <0.01 was considered statistically significant. The present study agrees with the preliminary bioinformatics analysis. In our experiments, the association of pathology with the genes was statistically significant for GRB2 and CBL (P <0.01), and it was not statistically significant for REL-A and NFKB1. This article lends support to our preliminary hypothesis that assigned an important role in refractory aggressive periodontitis to leader genes.

Can use of adaptive statistical iterative reconstruction reduce radiation dose in unenhanced head CT? An analysis of qualitative and quantitative image quality

PubMed Central

Heggen, Kristin Livelten; Pedersen, Hans Kristian; Andersen, Hilde Kjernlie; Martinsen, Anne Catrine T

2016-01-01

Background Iterative reconstruction can reduce image noise and thereby facilitate dose reduction. Purpose To evaluate qualitative and quantitative image quality for full dose and dose reduced head computed tomography (CT) protocols reconstructed using filtered back projection (FBP) and adaptive statistical iterative reconstruction (ASIR). Material and Methods Fourteen patients undergoing follow-up head CT were included. All patients underwent full dose (FD) exam and subsequent 15% dose reduced (DR) exam, reconstructed using FBP and 30% ASIR. Qualitative image quality was assessed using visual grading characteristics. Quantitative image quality was assessed using ROI measurements in cerebrospinal fluid (CSF), white matter, peripheral and central gray matter. Additionally, quantitative image quality was measured in Catphan and vendor’s water phantom. Results There was no significant difference in qualitative image quality between FD FBP and DR ASIR. Comparing same scan FBP versus ASIR, a noise reduction of 28.6% in CSF and between −3.7 and 3.5% in brain parenchyma was observed. Comparing FD FBP versus DR ASIR, a noise reduction of 25.7% in CSF, and −7.5 and 6.3% in brain parenchyma was observed. Image contrast increased in ASIR reconstructions. Contrast-to-noise ratio was improved in DR ASIR compared to FD FBP. In phantoms, noise reduction was in the range of 3 to 28% with image content. Conclusion There was no significant difference in qualitative image quality between full dose FBP and dose reduced ASIR. CNR improved in DR ASIR compared to FD FBP mostly due to increased contrast, not reduced noise. Therefore, we recommend using caution if reducing dose and applying ASIR to maintain image quality. PMID:27583169

Can use of adaptive statistical iterative reconstruction reduce radiation dose in unenhanced head CT? An analysis of qualitative and quantitative image quality.

PubMed

Østerås, Bjørn Helge; Heggen, Kristin Livelten; Pedersen, Hans Kristian; Andersen, Hilde Kjernlie; Martinsen, Anne Catrine T

2016-08-01

Iterative reconstruction can reduce image noise and thereby facilitate dose reduction. To evaluate qualitative and quantitative image quality for full dose and dose reduced head computed tomography (CT) protocols reconstructed using filtered back projection (FBP) and adaptive statistical iterative reconstruction (ASIR). Fourteen patients undergoing follow-up head CT were included. All patients underwent full dose (FD) exam and subsequent 15% dose reduced (DR) exam, reconstructed using FBP and 30% ASIR. Qualitative image quality was assessed using visual grading characteristics. Quantitative image quality was assessed using ROI measurements in cerebrospinal fluid (CSF), white matter, peripheral and central gray matter. Additionally, quantitative image quality was measured in Catphan and vendor's water phantom. There was no significant difference in qualitative image quality between FD FBP and DR ASIR. Comparing same scan FBP versus ASIR, a noise reduction of 28.6% in CSF and between -3.7 and 3.5% in brain parenchyma was observed. Comparing FD FBP versus DR ASIR, a noise reduction of 25.7% in CSF, and -7.5 and 6.3% in brain parenchyma was observed. Image contrast increased in ASIR reconstructions. Contrast-to-noise ratio was improved in DR ASIR compared to FD FBP. In phantoms, noise reduction was in the range of 3 to 28% with image content. There was no significant difference in qualitative image quality between full dose FBP and dose reduced ASIR. CNR improved in DR ASIR compared to FD FBP mostly due to increased contrast, not reduced noise. Therefore, we recommend using caution if reducing dose and applying ASIR to maintain image quality.

Improving statistical inference on pathogen densities estimated by quantitative molecular methods: malaria gametocytaemia as a case study.

PubMed

Walker, Martin; Basáñez, María-Gloria; Ouédraogo, André Lin; Hermsen, Cornelus; Bousema, Teun; Churcher, Thomas S

2015-01-16

Quantitative molecular methods (QMMs) such as quantitative real-time polymerase chain reaction (q-PCR), reverse-transcriptase PCR (qRT-PCR) and quantitative nucleic acid sequence-based amplification (QT-NASBA) are increasingly used to estimate pathogen density in a variety of clinical and epidemiological contexts. These methods are often classified as semi-quantitative, yet estimates of reliability or sensitivity are seldom reported. Here, a statistical framework is developed for assessing the reliability (uncertainty) of pathogen densities estimated using QMMs and the associated diagnostic sensitivity. The method is illustrated with quantification of Plasmodium falciparum gametocytaemia by QT-NASBA. The reliability of pathogen (e.g. gametocyte) densities, and the accompanying diagnostic sensitivity, estimated by two contrasting statistical calibration techniques, are compared; a traditional method and a mixed model Bayesian approach. The latter accounts for statistical dependence of QMM assays run under identical laboratory protocols and permits structural modelling of experimental measurements, allowing precision to vary with pathogen density. Traditional calibration cannot account for inter-assay variability arising from imperfect QMMs and generates estimates of pathogen density that have poor reliability, are variable among assays and inaccurately reflect diagnostic sensitivity. The Bayesian mixed model approach assimilates information from replica QMM assays, improving reliability and inter-assay homogeneity, providing an accurate appraisal of quantitative and diagnostic performance. Bayesian mixed model statistical calibration supersedes traditional techniques in the context of QMM-derived estimates of pathogen density, offering the potential to improve substantially the depth and quality of clinical and epidemiological inference for a wide variety of pathogens.

Mapping Quantitative Traits in Unselected Families: Algorithms and Examples

PubMed Central

Dupuis, Josée; Shi, Jianxin; Manning, Alisa K.; Benjamin, Emelia J.; Meigs, James B.; Cupples, L. Adrienne; Siegmund, David

2009-01-01

Linkage analysis has been widely used to identify from family data genetic variants influencing quantitative traits. Common approaches have both strengths and limitations. Likelihood ratio tests typically computed in variance component analysis can accommodate large families but are highly sensitive to departure from normality assumptions. Regression-based approaches are more robust but their use has primarily been restricted to nuclear families. In this paper, we develop methods for mapping quantitative traits in moderately large pedigrees. Our methods are based on the score statistic which in contrast to the likelihood ratio statistic, can use nonparametric estimators of variability to achieve robustness of the false positive rate against departures from the hypothesized phenotypic model. Because the score statistic is easier to calculate than the likelihood ratio statistic, our basic mapping methods utilize relatively simple computer code that performs statistical analysis on output from any program that computes estimates of identity-by-descent. This simplicity also permits development and evaluation of methods to deal with multivariate and ordinal phenotypes, and with gene-gene and gene-environment interaction. We demonstrate our methods on simulated data and on fasting insulin, a quantitative trait measured in the Framingham Heart Study. PMID:19278016

Detection and semi-quantification of Strongylus vulgaris DNA in equine faeces by real-time quantitative PCR.

PubMed

Nielsen, Martin K; Peterson, David S; Monrad, Jesper; Thamsborg, Stig M; Olsen, Susanne N; Kaplan, Ray M

2008-03-01

Strongylus vulgaris is an important strongyle nematode with high pathogenic potential infecting horses world-wide. Several decades of intensive anthelmintic use has virtually eliminated clinical disease caused by S. vulgaris, but has also caused high levels of anthelmintic resistance in equine small strongyle (cyathostomin) nematodes. Recommendations aimed at limiting the development of anthelmintic resistance by reducing treatment intensity raises a simultaneous demand for reliable and accurate diagnostic tools for detecting important parasitic pathogens. Presently, the only means available to differentiate among strongyle species in a faecal sample is by identifying individual L3 larvae following a two week coproculture procedure. The aim of the present study is to overcome this diagnostic obstacle by developing a fluorescence-based quantitative PCR assay capable of identifying S. vulgaris eggs in faecal samples from horses. Species-specific primers and a TaqMan probe were designed by alignment of published ribosomal DNA sequences of the second internal transcribed spacer of cyathostomin and Strongylus spp. nematodes. The assay was tested for specificity and optimized using genomic DNA extracted from identified male worms of Strongylus and cyathostomin species. In addition, eggs were collected from adult female worms and used to evaluate the quantitative potential of the assay. Statistically significant linear relationships were found between egg numbers and cycle of threshold (Ct) values. PCR results were unaffected by the presence of cyathostomin DNA in the sample and there was no indication of PCR inhibition by faecal sources. A field evaluation on faecal samples obtained from four Danish horse farms revealed a good agreement with the traditional larval culture (kappa-value=0.78), but with a significantly higher performance of the PCR assay. An association between Ct values and S. vulgaris larval counts was statistically significant. The present assay can reliably and semi-quantitatively detect minute quantities of S. vulgaris eggs in faecal samples.

Developing Sampling Frame for Case Study: Challenges and Conditions

ERIC Educational Resources Information Center

Ishak, Noriah Mohd; Abu Bakar, Abu Yazid

2014-01-01

Due to statistical analysis, the issue of random sampling is pertinent to any quantitative study. Unlike quantitative study, the elimination of inferential statistical analysis, allows qualitative researchers to be more creative in dealing with sampling issue. Since results from qualitative study cannot be generalized to the bigger population,…

Analysis of chronic aortic regurgitation by 2D and 3D echocardiography and cardiac MRI

PubMed Central

Stoebe, Stephan; Metze, Michael; Jurisch, Daniel; Tayal, Bhupendar; Solty, Kilian; Laufs, Ulrich; Pfeiffer, Dietrich; Hagendorff, Andreas

2018-01-01

Purpose The study compares the feasibility of the quantitative volumetric and semi-quantitative approach for quantification of chronic aortic regurgitation (AR) using different imaging modalities. Methods Left ventricular (LV) volumes, regurgitant volumes (RVol) and regurgitant fractions (RF) were assessed retrospectively by 2D, 3D echocardiography and cMRI in 55 chronic AR patients. Semi-quantitative parameters were assessed by 2D echocardiography. Results 22 (40%) patients had mild, 25 (46%) moderate and 8 (14%) severe AR. The quantitative volumetric approach was feasible using 2D, 3D echocardiography and cMRI, whereas the feasibility of semi-quantitative parameters varied considerably. LV volume (LVEDV, LVESV, SVtot) analyses showed good correlations between the different imaging modalities, although significantly increased LV volumes were assessed by cMRI. RVol was significantly different between 2D/3D echocardiography and 2D echocardiography/cMRI but was not significantly different between 3D echocardiography/cMRI. RF was not statistically different between 2D echocardiography/cMRI and 3D echocardiography/cMRI showing poor correlations (r < 0.5) between the different imaging modalities. For AR grading by RF, moderate agreement was observed between 2D/3D echocardiography and 2D echocardiography/cMRI and good agreement was observed between 3D echocardiography/cMRI. Conclusion Semi-quantitative parameters are difficult to determine by 2D echocardiography in clinical routine. The quantitative volumetric RF assessment seems to be feasible and can be discussed as an alternative approach in chronic AR. However, RVol and RF did not correlate well between the different imaging modalities. The best agreement for grading of AR severity by RF was observed between 3D echocardiography and cMRI. LV volumes can be verified by different approaches and different imaging modalities. PMID:29519957

Comparison of qualitative and quantitative CT and MRI parameters for monitoring of longitudinal spine involvement in patients with multiple myeloma.

PubMed

Horger, M; Fritz, J; Thaiss, W M; Ditt, H; Weisel, K; Haap, M; Kloth, Christopher

2018-03-01

To compare qualitative and quantitative computed tomography (CT) and magnetic resonance imaging (MRI) parameters for longitudinal disease monitoring of multiple myeloma (MM) of the axial skeleton. We included 31 consecutive patients (17 m; mean age 59.20 ± 8.08 years) with MM, who underwent all baseline (n = 31) and at least one or more (n = 47) follow-up examinations consisting of multi-parametric non-enhanced whole-body MRI ( WB MRI) and non-enhanced whole-body reduced-dose thin-section MDCT (NEWBMDCT) between 06/2013 and 09/2016. We classified response according to qualitative CT criteria into progression (PD), stable(SD), partial/very good partial (PR/VGPR) and complete response(CR), grouping the latter three together for statistical analysis because CT cannot reliably assess PR and CR. Qualitative MR-response criteria were defined and grouped similarly to CT using longitudinal quantification of signal-intensity changes on T1w/STIR/ T2*w and calculating ADC-values. Standard of reference was the hematological laboratory (M-gradient). Hematological response categories were CR (14/47, 29.7%), PR (2/47, 4.2%), SD (16/47, 34.0%) and PD (15/47, 29.9%). Qualitative-CT-evaluation showed PD in 12/47 (25.5%) and SD/PR/VGPR/CR in 35/47 (74.5%) cases. These results were confirmed by quantitative-CT in all focal lytic lesions (p < 0.001). Quantitative-CT at sites with diffuse bone involvement showed significant increase of maximum bone attenuation (p < 0.001*) and significant decrease of minimal bone (p < 0.002*) in the SD/PR/VGPR/CR group. Qualitative MRI showed PD in 14/47 (29.7%) and SD/PR/VGPR/CR in 33/47 (70.3%). Quantitative MRI diagnosis showed a statistically significant decrease in signal intensity on short tau inversion recovery sequences (STIR) in bone marrow in patients with diffuse bone marrow involvement achieving SD/PR/VGPR/CR (p < 0.001*). Imaging response monitoring using MRI is superior to CT only if qualitative parameters are used, whereas there was no definite benefit from using quantitative parameters with either CT or MRI.

Teacher Self-Efficacy: A Link to Student Achievement in English Language and Mathematics in Belizean Primary Schools

ERIC Educational Resources Information Center

Alvarez-Nunez, Tanya Mae

2012-01-01

Scope and Method of Study: This quantitative, non-experimental study sought to determine if a statistically significant difference existed in student achievement on the PSE exam in Belizean primary schools for students who have teachers with varying levels of self-efficacy (high, medium and low). The Teacher Efficacy Scale (TES), which captures…

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…

Academic Rigor and Economic Value: GED[R] and High School Students' Perceptions and Misperceptions of the GED[R] vs. the High School Diploma

ERIC Educational Resources Information Center

Horne, Lela M.; Rachal, John R.; Shelley, Kyna

2012-01-01

A mixed methods framework utilized quantitative and qualitative data to determine whether statistically significant differences existed between high school and GED[R] student perceptions of credential value. An exploratory factor analysis (n=326) extracted four factors and then a MANOVA procedure was performed with a stratified quota sample…

Quantitative Susceptibility Mapping by Inversion of a Perturbation Field Model: Correlation with Brain Iron in Normal Aging

PubMed Central

Poynton, Clare; Jenkinson, Mark; Adalsteinsson, Elfar; Sullivan, Edith V.; Pfefferbaum, Adolf; Wells, William

2015-01-01

There is increasing evidence that iron deposition occurs in specific regions of the brain in normal aging and neurodegenerative disorders such as Parkinson's, Huntington's, and Alzheimer's disease. Iron deposition changes the magnetic susceptibility of tissue, which alters the MR signal phase, and allows estimation of susceptibility differences using quantitative susceptibility mapping (QSM). We present a method for quantifying susceptibility by inversion of a perturbation model, or ‘QSIP’. The perturbation model relates phase to susceptibility using a kernel calculated in the spatial domain, in contrast to previous Fourier-based techniques. A tissue/air susceptibility atlas is used to estimate B0 inhomogeneity. QSIP estimates in young and elderly subjects are compared to postmortem iron estimates, maps of the Field-Dependent Relaxation Rate Increase (FDRI), and the L1-QSM method. Results for both groups showed excellent agreement with published postmortem data and in-vivo FDRI: statistically significant Spearman correlations ranging from Rho = 0.905 to Rho = 1.00 were obtained. QSIP also showed improvement over FDRI and L1-QSM: reduced variance in susceptibility estimates and statistically significant group differences were detected in striatal and brainstem nuclei, consistent with age-dependent iron accumulation in these regions. PMID:25248179

A Prospective, Matched Comparison Study of SUV Measurements From Time-of-Flight Versus Non-Time-of-Flight PET/CT Scanners.

PubMed

Thompson, Holly M; Minamimoto, Ryogo; Jamali, Mehran; Barkhodari, Amir; von Eyben, Rie; Iagaru, Andrei

2016-07-01

As quantitative F-FDG PET numbers and pooling of results from different PET/CT scanners become more influential in the management of patients, it becomes imperative that we fully interrogate differences between scanners to fully understand the degree of scanner bias on the statistical power of studies. Participants with body mass index (BMI) greater than 25, scheduled on a time-of-flight (TOF)-capable PET/CT scanner, had a consecutive scan on a non-TOF-capable PET/CT scanner and vice versa. SUVmean in various tissues and SUVmax of malignant lesions were measured from both scans, matched to each subject. Data were analyzed using a mixed-effects model, and statistical significance was determined using equivalence testing, with P < 0.05 being significant. Equivalence was established in all baseline organs, except the cerebellum, matched per patient between scanner types. Mixed-effects method analysis of lesions, repeated between scan types and matched per patient, demonstrated good concordance between scanner types. Patients could be scanned on either a TOF or non-TOF-capable PET/CT scanner without clinical compromise to quantitative SUV measurements.

A review of empirical research related to the use of small quantitative samples in clinical outcome scale development.

PubMed

Houts, Carrie R; Edwards, Michael C; Wirth, R J; Deal, Linda S

2016-11-01

There has been a notable increase in the advocacy of using small-sample designs as an initial quantitative assessment of item and scale performance during the scale development process. This is particularly true in the development of clinical outcome assessments (COAs), where Rasch analysis has been advanced as an appropriate statistical tool for evaluating the developing COAs using a small sample. We review the benefits such methods are purported to offer from both a practical and statistical standpoint and detail several problematic areas, including both practical and statistical theory concerns, with respect to the use of quantitative methods, including Rasch-consistent methods, with small samples. The feasibility of obtaining accurate information and the potential negative impacts of misusing large-sample statistical methods with small samples during COA development are discussed.

Development of CD3 cell quantitation algorithms for renal allograft biopsy rejection assessment utilizing open source image analysis software.

PubMed

Moon, Andres; Smith, Geoffrey H; Kong, Jun; Rogers, Thomas E; Ellis, Carla L; Farris, Alton B Brad

2018-02-01

Renal allograft rejection diagnosis depends on assessment of parameters such as interstitial inflammation; however, studies have shown interobserver variability regarding interstitial inflammation assessment. Since automated image analysis quantitation can be reproducible, we devised customized analysis methods for CD3+ T-cell staining density as a measure of rejection severity and compared them with established commercial methods along with visual assessment. Renal biopsy CD3 immunohistochemistry slides (n = 45), including renal allografts with various degrees of acute cellular rejection (ACR) were scanned for whole slide images (WSIs). Inflammation was quantitated in the WSIs using pathologist visual assessment, commercial algorithms (Aperio nuclear algorithm for CD3+ cells/mm 2 and Aperio positive pixel count algorithm), and customized open source algorithms developed in ImageJ with thresholding/positive pixel counting (custom CD3+%) and identification of pixels fulfilling "maxima" criteria for CD3 expression (custom CD3+ cells/mm 2 ). Based on visual inspections of "markup" images, CD3 quantitation algorithms produced adequate accuracy. Additionally, CD3 quantitation algorithms correlated between each other and also with visual assessment in a statistically significant manner (r = 0.44 to 0.94, p = 0.003 to < 0.0001). Methods for assessing inflammation suggested a progression through the tubulointerstitial ACR grades, with statistically different results in borderline versus other ACR types, in all but the custom methods. Assessment of CD3-stained slides using various open source image analysis algorithms presents salient correlations with established methods of CD3 quantitation. These analysis techniques are promising and highly customizable, providing a form of on-slide "flow cytometry" that can facilitate additional diagnostic accuracy in tissue-based assessments.

A Pilot Study of the Noninvasive Assessment of the Lung Microbiota as a Potential Tool for the Early Diagnosis of Ventilator-Associated Pneumonia

PubMed Central

Brady, Jacob S.; Romano-Keeler, Joann; Drake, Wonder P.; Norris, Patrick R.; Jenkins, Judith M.; Isaacs, Richard J.; Boczko, Erik M.

2015-01-01

BACKGROUND: Ventilator-associated pneumonia (VAP) remains a common complication in critically ill surgical patients, and its diagnosis remains problematic. Exhaled breath contains aerosolized droplets that reflect the lung microbiota. We hypothesized that exhaled breath condensate fluid (EBCF) in hygroscopic condenser humidifier/heat and moisture exchanger (HCH/HME) filters would contain bacterial DNA that qualitatively and quantitatively correlate with pathogens isolated from quantitative BAL samples obtained for clinical suspicion of pneumonia. METHODS: Forty-eight adult patients who were mechanically ventilated and undergoing quantitative BAL (n = 51) for suspected pneumonia in the surgical ICU were enrolled. Per protocol, patients fulfilling VAP clinical criteria undergo quantitative BAL bacterial culture. Immediately prior to BAL, time-matched HCH/HME filters were collected for study of EBCF by real-time polymerase chain reaction. Additionally, convenience samples of serially collected filters in patients with BAL-diagnosed VAP were analyzed. RESULTS: Forty-nine of 51 time-matched EBCF/BAL fluid samples were fully concordant (concordance > 95% by κ statistic) relative to identified pathogens and strongly correlated with clinical cultures. Regression analysis of quantitative bacterial DNA in paired samples revealed a statistically significant positive correlation (r = 0.85). In a convenience sample, qualitative and quantitative polymerase chain reaction analysis of serial HCH/HME samples for bacterial DNA demonstrated an increase in load that preceded the suspicion of pneumonia. CONCLUSIONS: Bacterial DNA within EBCF demonstrates a high correlation with BAL fluid and clinical cultures. Bacterial DNA within EBCF increases prior to the suspicion of pneumonia. Further study of this novel approach may allow development of a noninvasive tool for the early diagnosis of VAP. PMID:25474571

3D printing PLGA: a quantitative examination of the effects of polymer composition and printing parameters on print resolution

PubMed Central

Guo, Ting; Holzberg, Timothy R; Lim, Casey G; Gao, Feng; Gargava, Ankit; Trachtenberg, Jordan E; Mikos, Antonios G; Fisher, John P

2018-01-01

In the past few decades, 3D printing has played a significant role in fabricating scaffolds with consistent, complex structure that meet patient-specific needs in future clinical applications. Although many studies have contributed to this emerging field of additive manufacturing, which includes material development and computer-aided scaffold design, current quantitative analyses do not correlate material properties, printing parameters, and printing outcomes to a great extent. A model that correlates these properties has tremendous potential to standardize 3D printing for tissue engineering and biomaterial science. In this study, we printed poly(lactic-co-glycolic acid) (PLGA) utilizing a direct melt extrusion technique without additional ingredients. We investigated PLGA with various lactic acid: glycolic acid (LA:GA) molecular weight ratios and end caps to demonstrate the dependence of the extrusion process on the polymer composition. Micro-computed tomography was then used to evaluate printed scaffolds containing different LA:GA ratios, composed of different fiber patterns, and processed under different printing conditions. We built a statistical model to reveal the correlation and predominant factors that determine printing precision. Our model showed a strong linear relationship between the actual and predicted precision under different combinations of printing conditions and material compositions. This quantitative examination establishes a significant foreground to 3D print biomaterials following a systematic fabrication procedure. Additionally, our proposed statistical models can be applied to couple specific biomaterials and 3D printing applications for patient implants with particular requirements. PMID:28244880

Potential predictors of risk sexual behavior among private college students in Mekelle City, North Ethiopia.

PubMed

Gebresllasie, Fanna; Tsadik, Mache; Berhane, Eyoel

2017-01-01

Risk sexual practice among students from public universities/colleges is common in Ethiopia. However, little has been known about risk sexual behavior of students in private colleges where more students are potentially enrolled. Therefore, this study aimed to assess the magnitude of risky sexual behaviors and predictors among students of Private Colleges in Mekelle City. A mixed design of both quantitative and qualitative methods was used among 627 randomly selected students of private colleges from February to march 2013. Self administered questionnaire and focus group discussion was used to collect data. A thematic content analysis was used for the qualitative part. For the quantitative study, Univariate, Bivariate and multivariable analysis was made using SPSS version 16 statistical package and p value less than 0.05 was used as cut off point for a statistical significance. Among the total 590 respondents, 151 (29.1%) have ever had sex. Among the sexually active students, 30.5% reported having had multiple sexual partners and consistent condom use was nearly 39%. In multivariable logistic regression analysis, variables such as sex, age group, sex last twelve months and condom use last twelve months was found significantly associated with risky sexual behavior. The findings of qualitative and quantitative study showed consistency in presence of risk factors. Finding of this study showed sexual risk behaviors is high among private colleges such as multiple sexual partners and substance use. So that colleges should emphasis on promoting healthy sexual and reproductive health programs.

3D printing PLGA: a quantitative examination of the effects of polymer composition and printing parameters on print resolution.

PubMed

Guo, Ting; Holzberg, Timothy R; Lim, Casey G; Gao, Feng; Gargava, Ankit; Trachtenberg, Jordan E; Mikos, Antonios G; Fisher, John P

2017-04-12

In the past few decades, 3D printing has played a significant role in fabricating scaffolds with consistent, complex structure that meet patient-specific needs in future clinical applications. Although many studies have contributed to this emerging field of additive manufacturing, which includes material development and computer-aided scaffold design, current quantitative analyses do not correlate material properties, printing parameters, and printing outcomes to a great extent. A model that correlates these properties has tremendous potential to standardize 3D printing for tissue engineering and biomaterial science. In this study, we printed poly(lactic-co-glycolic acid) (PLGA) utilizing a direct melt extrusion technique without additional ingredients. We investigated PLGA with various lactic acid:glycolic acid (LA:GA) molecular weight ratios and end caps to demonstrate the dependence of the extrusion process on the polymer composition. Micro-computed tomography was then used to evaluate printed scaffolds containing different LA:GA ratios, composed of different fiber patterns, and processed under different printing conditions. We built a statistical model to reveal the correlation and predominant factors that determine printing precision. Our model showed a strong linear relationship between the actual and predicted precision under different combinations of printing conditions and material compositions. This quantitative examination establishes a significant foreground to 3D print biomaterials following a systematic fabrication procedure. Additionally, our proposed statistical models can be applied to couple specific biomaterials and 3D printing applications for patient implants with particular requirements.

Institutional racism in public health contracting: Findings of a nationwide survey from New Zealand.

PubMed

Came, H; Doole, C; McKenna, B; McCreanor, T

2018-02-01

Public institutions within New Zealand have long been accused of mono-culturalism and institutional racism. This study sought to identify inconsistencies and bias by comparing government funded contracting processes for Māori public health providers (n = 60) with those of generic providers (n = 90). Qualitative and quantitative data were collected (November 2014-May 2015), through a nationwide telephone survey of public health providers, achieving a 75% response rate. Descriptive statistical analyses were applied to quantitative responses and an inductive approach was taken to analyse data from open-ended responses in the survey domains of relationships with portfolio contract managers, contracting and funding. The quantitative data showed four sites of statistically significant variation: length of contracts, intensity of monitoring, compliance costs and frequency of auditing. Non-significant data involved access to discretionary funding and cost of living adjustments, the frequency of monitoring, access to Crown (government) funders and representation on advisory groups. The qualitative material showed disparate provider experiences, dependent on individual portfolio managers, with nuanced differences between generic and Māori providers' experiences. This study showed that monitoring government performance through a nationwide survey was an innovative way to identify sites of institutional racism. In a policy context where health equity is a key directive to the health sector, this study suggests there is scope for New Zealand health funders to improve their contracting practices. Copyright © 2017 Elsevier Ltd. All rights reserved.

Visually estimated ejection fraction by two dimensional and triplane echocardiography is closely correlated with quantitative ejection fraction by real-time three dimensional echocardiography.

PubMed

Shahgaldi, Kambiz; Gudmundsson, Petri; Manouras, Aristomenis; Brodin, Lars-Ake; Winter, Reidar

2009-08-25

Visual assessment of left ventricular ejection fraction (LVEF) is often used in clinical routine despite general recommendations to use quantitative biplane Simpsons (BPS) measurements. Even thou quantitative methods are well validated and from many reasons preferable, the feasibility of visual assessment (eyeballing) is superior. There is to date only sparse data comparing visual EF assessment in comparison to quantitative methods available. The aim of this study was to compare visual EF assessment by two-dimensional echocardiography (2DE) and triplane echocardiography (TPE) using quantitative real-time three-dimensional echocardiography (RT3DE) as the reference method. Thirty patients were enrolled in the study. Eyeballing EF was assessed using apical 4-and 2 chamber views and TP mode by two experienced readers blinded to all clinical data. The measurements were compared to quantitative RT3DE. There were an excellent correlation between eyeballing EF by 2D and TP vs 3DE (r = 0.91 and 0.95 respectively) without any significant bias (-0.5 +/- 3.7% and -0.2 +/- 2.9% respectively). Intraobserver variability was 3.8% for eyeballing 2DE, 3.2% for eyeballing TP and 2.3% for quantitative 3D-EF. Interobserver variability was 7.5% for eyeballing 2D and 8.4% for eyeballing TP. Visual estimation of LVEF both using 2D and TP by an experienced reader correlates well with quantitative EF determined by RT3DE. There is an apparent trend towards a smaller variability using TP in comparison to 2D, this was however not statistically significant.

Quantitative determination and validation of octreotide acetate using 1 H-NMR spectroscopy with internal standard method.

PubMed

Yu, Chen; Zhang, Qian; Xu, Peng-Yao; Bai, Yin; Shen, Wen-Bin; Di, Bin; Su, Meng-Xiang

2018-01-01

Quantitative nuclear magnetic resonance (qNMR) is a well-established technique in quantitative analysis. We presented a validated 1 H-qNMR method for assay of octreotide acetate, a kind of cyclic octopeptide. Deuterium oxide was used to remove the undesired exchangeable peaks, which was referred to as proton exchange, in order to make the quantitative signals isolated in the crowded spectrum of the peptide and ensure precise quantitative analysis. Gemcitabine hydrochloride was chosen as the suitable internal standard. Experimental conditions, including relaxation delay time, the numbers of scans, and pulse angle, were optimized first. Then method validation was carried out in terms of selectivity, stability, linearity, precision, and robustness. The assay result was compared with that by means of high performance liquid chromatography, which is provided by Chinese Pharmacopoeia. The statistical F test, Student's t test, and nonparametric test at 95% confidence level indicate that there was no significant difference between these two methods. qNMR is a simple and accurate quantitative tool with no need for specific corresponding reference standards. It has the potential of the quantitative analysis of other peptide drugs and standardization of the corresponding reference standards. Copyright © 2017 John Wiley & Sons, Ltd.

The effects of compensatory workplace exercises to reduce work-related stress and musculoskeletal pain1

PubMed Central

de Freitas-Swerts, Fabiana Cristina Taubert; Robazzi, Maria Lúcia do Carmo Cruz

2014-01-01

OBJECTIVES: to assess the effect of a compensatory workplace exercise program on workers with the purpose of reducing work-related stress and musculoskeletal pain. METHOD: quasi-experimental research with quantitative analysis of the data, involving 30 administrative workers from a Higher Education Public Institution. For data collection, questionnaires were used to characterize the workers, as well as the Workplace Stress Scale and the Corlett Diagram. The research took place in three stages: first: pre-test with the application of the questionnaires to the subjects; second: Workplace Exercise taking place twice a week, for 15 minutes, during a period of 10 weeks; third: post-test in which the subjects answered the questionnaires again. For data analysis, the descriptive statistics and non-parametric statistics were used through the Wilcoxon Test. RESULTS: work-related stress was present in the assessed workers, but there was no statistically significant reduction in the scores after undergoing Workplace Exercise. However, there was a statistically significant pain reduction in the neck, cervical, upper, middle and lower back, right thigh, left leg, right ankle and feet. CONCLUSION: the Workplace Exercise promoted a significant pain reduction in the spine, but did not result in a significant reduction in the levels of work-related stress. PMID:25296147

Biostatistical analysis of quantitative immunofluorescence microscopy images.

PubMed

Giles, C; Albrecht, M A; Lam, V; Takechi, R; Mamo, J C

2016-12-01

Semiquantitative immunofluorescence microscopy has become a key methodology in biomedical research. Typical statistical workflows are considered in the context of avoiding pseudo-replication and marginalising experimental error. However, immunofluorescence microscopy naturally generates hierarchically structured data that can be leveraged to improve statistical power and enrich biological interpretation. Herein, we describe a robust distribution fitting procedure and compare several statistical tests, outlining their potential advantages/disadvantages in the context of biological interpretation. Further, we describe tractable procedures for power analysis that incorporates the underlying distribution, sample size and number of images captured per sample. The procedures outlined have significant potential for increasing understanding of biological processes and decreasing both ethical and financial burden through experimental optimization. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

Quantitative skills as a graduate learning outcome of university science degree programmes: student performance explored through theplanned-enacted-experiencedcurriculum model

NASA Astrophysics Data System (ADS)

Matthews, Kelly E.; Adams, Peter; Goos, Merrilyn

2016-07-01

Application of mathematical and statistical thinking and reasoning, typically referred to as quantitative skills, is essential for university bioscience students. First, this study developed an assessment task intended to gauge graduating students' quantitative skills. The Quantitative Skills Assessment of Science Students (QSASS) was the result, which examined 10 mathematical and statistical sub-topics. Second, the study established an evidential baseline of students' quantitative skills performance and confidence levels by piloting the QSASS with 187 final-year biosciences students at a research-intensive university. The study is framed within the planned-enacted-experienced curriculum model and contributes to science reform efforts focused on enhancing the quantitative skills of university graduates, particularly in the biosciences. The results found, on average, weak performance and low confidence on the QSASS, suggesting divergence between academics' intentions and students' experiences of learning quantitative skills. Implications for curriculum design and future studies are discussed.

Detecting cell death with optical coherence tomography and envelope statistics

NASA Astrophysics Data System (ADS)

Farhat, Golnaz; Yang, Victor X. D.; Czarnota, Gregory J.; Kolios, Michael C.

2011-02-01

Currently no standard clinical or preclinical noninvasive method exists to monitor cell death based on morphological changes at the cellular level. In our past work we have demonstrated that quantitative high frequency ultrasound imaging can detect cell death in vitro and in vivo. In this study we apply quantitative methods previously used with high frequency ultrasound to optical coherence tomography (OCT) to detect cell death. The ultimate goal of this work is to use these methods for optically-based clinical and preclinical cancer treatment monitoring. Optical coherence tomography data were acquired from acute myeloid leukemia cells undergoing three modes of cell death. Significant increases in integrated backscatter were observed for cells undergoing apoptosis and mitotic arrest, while necrotic cells induced a decrease. These changes appear to be linked to structural changes observed in histology obtained from the cell samples. Signal envelope statistics were analyzed from fittings of the generalized gamma distribution to histograms of envelope intensities. The parameters from this distribution demonstrated sensitivities to morphological changes in the cell samples. These results indicate that OCT integrated backscatter and first order envelope statistics can be used to detect and potentially differentiate between modes of cell death in vitro.

A tutorial in displaying mass spectrometry-based proteomic data using heat maps.

PubMed

Key, Melissa

2012-01-01

Data visualization plays a critical role in interpreting experimental results of proteomic experiments. Heat maps are particularly useful for this task, as they allow us to find quantitative patterns across proteins and biological samples simultaneously. The quality of a heat map can be vastly improved by understanding the options available to display and organize the data in the heat map. This tutorial illustrates how to optimize heat maps for proteomics data by incorporating known characteristics of the data into the image. First, the concepts used to guide the creating of heat maps are demonstrated. Then, these concepts are applied to two types of analysis: visualizing spectral features across biological samples, and presenting the results of tests of statistical significance. For all examples we provide details of computer code in the open-source statistical programming language R, which can be used for biologists and clinicians with little statistical background. Heat maps are a useful tool for presenting quantitative proteomic data organized in a matrix format. Understanding and optimizing the parameters used to create the heat map can vastly improve both the appearance and the interoperation of heat map data.

Tension between the theoretical thinking and the empirical method: is it an inevitable fate for psychology?

PubMed

Omi, Yasuhiro

2012-03-01

This paper will start from focusing on the limitations of quantitative approach in psychology from three viewpoints. First--data collection, especially experiments and questionnaires as two major methods of quantitative approach. The second limitation is data aggregation, followed by the third--statistical significance testing. After that, recent spread of qualitative approach as another option for one of psychological methods will be introduced and a controversy surrounding epistemology of qualitative approach will be also introduced. Finally, it will be discussed that accumulation of faithful descriptions on reality, especially from qualitative approach, would be needed for producing creative research.

Management of natural resources through automatic cartographic inventory

NASA Technical Reports Server (NTRS)

Rey, P.; Gourinard, Y.; Cambou, F. (Principal Investigator)

1973-01-01

The author has identified the following significant results. Significant results of the ARNICA program from August 1972 - January 1973 have been: (1) establishment of image to object correspondence codes for all types of soil use and forestry in northern Spain; (2) establishment of a transfer procedure between qualitative (remote identification and remote interpretation) and quantitative (numerization, storage, automatic statistical cartography) use of images; (3) organization of microdensitometric data processing and automatic cartography software; and (4) development of a system for measuring reflectance simultaneous with imagery.

Measuring Technological and Content Knowledge of Undergraduate Primary Teachers in Mathematics

NASA Astrophysics Data System (ADS)

Doukakis, Spyros; Chionidou-Moskofoglou, Maria; Mangina-Phelan, Eleni; Roussos, Petros

Twenty-five final-year undergraduate students of primary education who were attending a course on mathematics education participated in a research project during the 2009 spring semester. A repeated measures experimental design was used. Quantitative data on students' computer attitudes, self-efficacy in ICT, attitudes toward educational software, and self-efficacy in maths were collected. Data analysis showed a statistically non-significant improvement on participants' computer attitudes and self-efficacy in ICT and ES, but a significant improvement of self-efficacy in mathematics.

QuantFusion: Novel Unified Methodology for Enhanced Coverage and Precision in Quantifying Global Proteomic Changes in Whole Tissues.

PubMed

Gunawardena, Harsha P; O'Brien, Jonathon; Wrobel, John A; Xie, Ling; Davies, Sherri R; Li, Shunqiang; Ellis, Matthew J; Qaqish, Bahjat F; Chen, Xian

2016-02-01

Single quantitative platforms such as label-based or label-free quantitation (LFQ) present compromises in accuracy, precision, protein sequence coverage, and speed of quantifiable proteomic measurements. To maximize the quantitative precision and the number of quantifiable proteins or the quantifiable coverage of tissue proteomes, we have developed a unified approach, termed QuantFusion, that combines the quantitative ratios of all peptides measured by both LFQ and label-based methodologies. Here, we demonstrate the use of QuantFusion in determining the proteins differentially expressed in a pair of patient-derived tumor xenografts (PDXs) representing two major breast cancer (BC) subtypes, basal and luminal. Label-based in-spectra quantitative peptides derived from amino acid-coded tagging (AACT, also known as SILAC) of a non-malignant mammary cell line were uniformly added to each xenograft with a constant predefined ratio, from which Ratio-of-Ratio estimates were obtained for the label-free peptides paired with AACT peptides in each PDX tumor. A mixed model statistical analysis was used to determine global differential protein expression by combining complementary quantifiable peptide ratios measured by LFQ and Ratio-of-Ratios, respectively. With minimum number of replicates required for obtaining the statistically significant ratios, QuantFusion uses the distinct mechanisms to "rescue" the missing data inherent to both LFQ and label-based quantitation. Combined quantifiable peptide data from both quantitative schemes increased the overall number of peptide level measurements and protein level estimates. In our analysis of the PDX tumor proteomes, QuantFusion increased the number of distinct peptide ratios by 65%, representing differentially expressed proteins between the BC subtypes. This quantifiable coverage improvement, in turn, not only increased the number of measurable protein fold-changes by 8% but also increased the average precision of quantitative estimates by 181% so that some BC subtypically expressed proteins were rescued by QuantFusion. Thus, incorporating data from multiple quantitative approaches while accounting for measurement variability at both the peptide and global protein levels make QuantFusion unique for obtaining increased coverage and quantitative precision for tissue proteomes. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Using Statistics to Lie, Distort, and Abuse Data

ERIC Educational Resources Information Center

Bintz, William; Moore, Sara; Adams, Cheryll; Pierce, Rebecca

2009-01-01

Statistics is a branch of mathematics that involves organization, presentation, and interpretation of data, both quantitative and qualitative. Data do not lie, but people do. On the surface, quantitative data are basically inanimate objects, nothing more than lifeless and meaningless symbols that appear on a page, calculator, computer, or in one's…

QuantCrit: Education, Policy, "Big Data" and Principles for a Critical Race Theory of Statistics

ERIC Educational Resources Information Center

Gillborn, David; Warmington, Paul; Demack, Sean

2018-01-01

Quantitative research enjoys heightened esteem among policy-makers, media, and the general public. Whereas qualitative research is frequently dismissed as subjective and impressionistic, statistics are often assumed to be objective and factual. We argue that these distinctions are wholly false; quantitative data is no less socially constructed…

Quantitative 3D breast magnetic resonance imaging fibroglandular tissue analysis and correlation with qualitative assessments: a feasibility study.

PubMed

Ha, Richard; Mema, Eralda; Guo, Xiaotao; Mango, Victoria; Desperito, Elise; Ha, Jason; Wynn, Ralph; Zhao, Binsheng

2016-04-01

The amount of fibroglandular tissue (FGT) has been linked to breast cancer risk based on mammographic density studies. Currently, the qualitative assessment of FGT on mammogram (MG) and magnetic resonance imaging (MRI) is prone to intra and inter-observer variability. The purpose of this study is to develop an objective quantitative FGT measurement tool for breast MRI that could provide significant clinical value. An IRB approved study was performed. Sixty breast MRI cases with qualitative assessment of mammographic breast density and MRI FGT were randomly selected for quantitative analysis from routine breast MRIs performed at our institution from 1/2013 to 12/2014. Blinded to the qualitative data, whole breast and FGT contours were delineated on T1-weighted pre contrast sagittal images using an in-house, proprietary segmentation algorithm which combines the region-based active contours and a level set approach. FGT (%) was calculated by: [segmented volume of FGT (mm(3))/(segmented volume of whole breast (mm(3))] ×100. Statistical correlation analysis was performed between quantified FGT (%) on MRI and qualitative assessments of mammographic breast density and MRI FGT. There was a significant positive correlation between quantitative MRI FGT assessment and qualitative MRI FGT (r=0.809, n=60, P<0.001) and mammographic density assessment (r=0.805, n=60, P<0.001). There was a significant correlation between qualitative MRI FGT assessment and mammographic density assessment (r=0.725, n=60, P<0.001). The four qualitative assessment categories of FGT correlated with the calculated mean quantitative FGT (%) of 4.61% (95% CI, 0-12.3%), 8.74% (7.3-10.2%), 18.1% (15.1-21.1%), 37.4% (29.5-45.3%). Quantitative measures of FGT (%) were computed with data derived from breast MRI and correlated significantly with conventional qualitative assessments. This quantitative technique may prove to be a valuable tool in clinical use by providing computer generated standardized measurements with limited intra or inter-observer variability.

Quantitative Features of Liver Lesions, Lung Nodules, and Renal Stones at Multi-Detector Row CT Examinations: Dependency on Radiation Dose and Reconstruction Algorithm.

PubMed

Solomon, Justin; Mileto, Achille; Nelson, Rendon C; Roy Choudhury, Kingshuk; Samei, Ehsan

2016-04-01

To determine if radiation dose and reconstruction algorithm affect the computer-based extraction and analysis of quantitative imaging features in lung nodules, liver lesions, and renal stones at multi-detector row computed tomography (CT). Retrospective analysis of data from a prospective, multicenter, HIPAA-compliant, institutional review board-approved clinical trial was performed by extracting 23 quantitative imaging features (size, shape, attenuation, edge sharpness, pixel value distribution, and texture) of lesions on multi-detector row CT images of 20 adult patients (14 men, six women; mean age, 63 years; range, 38-72 years) referred for known or suspected focal liver lesions, lung nodules, or kidney stones. Data were acquired between September 2011 and April 2012. All multi-detector row CT scans were performed at two different radiation dose levels; images were reconstructed with filtered back projection, adaptive statistical iterative reconstruction, and model-based iterative reconstruction (MBIR) algorithms. A linear mixed-effects model was used to assess the effect of radiation dose and reconstruction algorithm on extracted features. Among the 23 imaging features assessed, radiation dose had a significant effect on five, three, and four of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). Adaptive statistical iterative reconstruction had a significant effect on three, one, and one of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). MBIR reconstruction had a significant effect on nine, 11, and 15 of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). Of note, the measured size of lung nodules and renal stones with MBIR was significantly different than those for the other two algorithms (P < .002 for all comparisons). Although lesion texture was significantly affected by the reconstruction algorithm used (average of 3.33 features affected by MBIR throughout lesion types; P < .002, for all comparisons), no significant effect of the radiation dose setting was observed for all but one of the texture features (P = .002-.998). Radiation dose settings and reconstruction algorithms affect the extraction and analysis of quantitative imaging features in lesions at multi-detector row CT.

mapDIA: Preprocessing and statistical analysis of quantitative proteomics data from data independent acquisition mass spectrometry.

PubMed

Teo, Guoshou; Kim, Sinae; Tsou, Chih-Chiang; Collins, Ben; Gingras, Anne-Claude; Nesvizhskii, Alexey I; Choi, Hyungwon

2015-11-03

Data independent acquisition (DIA) mass spectrometry is an emerging technique that offers more complete detection and quantification of peptides and proteins across multiple samples. DIA allows fragment-level quantification, which can be considered as repeated measurements of the abundance of the corresponding peptides and proteins in the downstream statistical analysis. However, few statistical approaches are available for aggregating these complex fragment-level data into peptide- or protein-level statistical summaries. In this work, we describe a software package, mapDIA, for statistical analysis of differential protein expression using DIA fragment-level intensities. The workflow consists of three major steps: intensity normalization, peptide/fragment selection, and statistical analysis. First, mapDIA offers normalization of fragment-level intensities by total intensity sums as well as a novel alternative normalization by local intensity sums in retention time space. Second, mapDIA removes outlier observations and selects peptides/fragments that preserve the major quantitative patterns across all samples for each protein. Last, using the selected fragments and peptides, mapDIA performs model-based statistical significance analysis of protein-level differential expression between specified groups of samples. Using a comprehensive set of simulation datasets, we show that mapDIA detects differentially expressed proteins with accurate control of the false discovery rates. We also describe the analysis procedure in detail using two recently published DIA datasets generated for 14-3-3β dynamic interaction network and prostate cancer glycoproteome. The software was written in C++ language and the source code is available for free through SourceForge website http://sourceforge.net/projects/mapdia/.This article is part of a Special Issue entitled: Computational Proteomics. Copyright © 2015 Elsevier B.V. All rights reserved.

Characterization of a neutron sensitive MCP/Timepix detector for quantitative image analysis at a pulsed neutron source

NASA Astrophysics Data System (ADS)

Watanabe, Kenichi; Minniti, Triestino; Kockelmann, Winfried; Dalgliesh, Robert; Burca, Genoveva; Tremsin, Anton S.

2017-07-01

The uncertainties and the stability of a neutron sensitive MCP/Timepix detector when operating in the event timing mode for quantitative image analysis at a pulsed neutron source were investigated. The dominant component to the uncertainty arises from the counting statistics. The contribution of the overlap correction to the uncertainty was concluded to be negligible from considerations based on the error propagation even if a pixel occupation probability is more than 50%. We, additionally, have taken into account the multiple counting effect in consideration of the counting statistics. Furthermore, the detection efficiency of this detector system changes under relatively high neutron fluxes due to the ageing effects of current Microchannel Plates. Since this efficiency change is position-dependent, it induces a memory image. The memory effect can be significantly reduced with correction procedures using the rate equations describing the permanent gain degradation and the scrubbing effect on the inner surfaces of the MCP pores.

Quantitative single-molecule imaging by confocal laser scanning microscopy.

PubMed

Vukojevic, Vladana; Heidkamp, Marcus; Ming, Yu; Johansson, Björn; Terenius, Lars; Rigler, Rudolf

2008-11-25

A new approach to quantitative single-molecule imaging by confocal laser scanning microscopy (CLSM) is presented. It relies on fluorescence intensity distribution to analyze the molecular occurrence statistics captured by digital imaging and enables direct determination of the number of fluorescent molecules and their diffusion rates without resorting to temporal or spatial autocorrelation analyses. Digital images of fluorescent molecules were recorded by using fast scanning and avalanche photodiode detectors. In this way the signal-to-background ratio was significantly improved, enabling direct quantitative imaging by CLSM. The potential of the proposed approach is demonstrated by using standard solutions of fluorescent dyes, fluorescently labeled DNA molecules, quantum dots, and the Enhanced Green Fluorescent Protein in solution and in live cells. The method was verified by using fluorescence correlation spectroscopy. The relevance for biological applications, in particular, for live cell imaging, is discussed.

Quantitative assessment of oral mucosa and labial minor salivary glands in patients with Sjögren’s syndrome using swept source OCT

PubMed Central

Grulkowski, Ireneusz; Nowak, Jan K.; Karnowski, Karol; Zebryk, Paweł; Puszczewicz, Mariusz; Walkowiak, Jaroslaw; Wojtkowski, Maciej

2013-01-01

Three-dimensional imaging of the mucosa of the lower lip and labial minor salivary glands is demonstrated in vivo using swept source optical coherence tomography (OCT) system at 1310 nm with modified interface. Volumetric data sets of the inner surface of the lower lip covering ~230 mm2 field are obtained from patients with Sjögren’s syndrome and a control group. OCT enables high-resolution visualization of mucosal architecture using cross-sectional images as well as en-face projection images. Comprehensive morphometry of the labial minor salivary glands is performed, and statistical significance is assessed. Statistically significant differences in morphometric parameters are found when subgroups of patients with Sjögren’s syndrome are analyzed. PMID:24466492

Quantitative assessment of oral mucosa and labial minor salivary glands in patients with Sjögren's syndrome using swept source OCT.

PubMed

Grulkowski, Ireneusz; Nowak, Jan K; Karnowski, Karol; Zebryk, Paweł; Puszczewicz, Mariusz; Walkowiak, Jaroslaw; Wojtkowski, Maciej

2013-12-16

Three-dimensional imaging of the mucosa of the lower lip and labial minor salivary glands is demonstrated in vivo using swept source optical coherence tomography (OCT) system at 1310 nm with modified interface. Volumetric data sets of the inner surface of the lower lip covering ~230 mm(2) field are obtained from patients with Sjögren's syndrome and a control group. OCT enables high-resolution visualization of mucosal architecture using cross-sectional images as well as en-face projection images. Comprehensive morphometry of the labial minor salivary glands is performed, and statistical significance is assessed. Statistically significant differences in morphometric parameters are found when subgroups of patients with Sjögren's syndrome are analyzed.

[Study of the reliability in one dimensional size measurement with digital slit lamp microscope].

PubMed

Wang, Tao; Qi, Chaoxiu; Li, Qigen; Dong, Lijie; Yang, Jiezheng

2010-11-01

To study the reliability of digital slit lamp microscope as a tool for quantitative analysis in one dimensional size measurement. Three single-blinded observers acquired and repeatedly measured the images with a size of 4.00 mm and 10.00 mm on the vernier caliper, which simulatated the human eye pupil and cornea diameter under China-made digital slit lamp microscope in the objective magnification of 4 times, 10 times, 16 times, 25 times, 40 times and 4 times, 10 times, 16 times, respectively. The correctness and precision of measurement were compared. The images with 4 mm size were measured by three investigators and the average values were located between 3.98 to 4.06. For the images with 10.00 mm size, the average values fell within 10.00 ~ 10.04. Measurement results of 4.00 mm images showed, except A4, B25, C16 and C25, significant difference was noted between the measured value and the true value. Regarding measurement results of 10.00 mm iamges indicated, except A10, statistical significance was found between the measured value and the true value. In terms of comparing the results of the same size measured at different magnifications by the same investigator, except for investigators A's measurements of 10.00 mm dimension, the measurement results by all the remaining investigators presented statistical significance at different magnifications. Compared measurements of the same size with different magnifications, measurements of 4.00 mm in 4-fold magnification had no significant difference among the investigators', the remaining results were statistically significant. The coefficient of variation of all measurement results were less than 5%; as magnification increased, the coefficient of variation decreased. The measurement of digital slit lamp microscope in one-dimensional size has good reliability,and should be performed for reliability analysis before used for quantitative analysis to reduce systematic errors.

The Relationship of Academic Success and Selected Other Factors to Student Use of Library Materials at College of the Desert.

ERIC Educational Resources Information Center

Hostrop, Richard Winfred

This study found that, although some statistically-significant personal characteristics of students were associated with the use of library resources, they played only a minor role in the quantitive use of the materials. Instructors, in assigning term papers and speeches, provided the main impetus to student use of the library. Fewer than 5% of…

Nursing Students' Intrinsic Motivation and Performance on the Licensure Examination.

PubMed

Hackney, Michele G

Unsuccessful attempts at licensure adversely affect graduates, prelicensure nursing education programs, health care agencies, and ultimately, patient safety. The purpose of this quantitative, correlational study was to investigate the relationship between nursing students' intrinsic motivation and performance on the licensure examination. Nursing students responded to 12 questions related to reasons for learning as indicators of motivation type. Results indicated no statistically significant correlations between variables.

Introduction of an automated user-independent quantitative volumetric magnetic resonance imaging breast density measurement system using the Dixon sequence: comparison with mammographic breast density assessment.

PubMed

Wengert, Georg Johannes; Helbich, Thomas H; Vogl, Wolf-Dieter; Baltzer, Pascal; Langs, Georg; Weber, Michael; Bogner, Wolfgang; Gruber, Stephan; Trattnig, Siegfried; Pinker, Katja

2015-02-01

The purposes of this study were to introduce and assess an automated user-independent quantitative volumetric (AUQV) breast density (BD) measurement system on the basis of magnetic resonance imaging (MRI) using the Dixon technique as well as to compare it with qualitative and quantitative mammographic (MG) BD measurements. Forty-three women with normal mammogram results (Breast Imaging Reporting and Data System 1) were included in this institutional review board-approved prospective study. All participants were subjected to BD assessment with MRI using the following sequence with the Dixon technique (echo time/echo time, 6 milliseconds/2.45 milliseconds/2.67 milliseconds; 1-mm isotropic; 3 minutes 38 seconds). To test the reproducibility, a second MRI after patient repositioning was performed. The AUQV magnetic resonance (MR) BD measurement system automatically calculated percentage (%) BD. The qualitative BD assessment was performed using the American College of Radiology Breast Imaging Reporting and Data System BD categories. Quantitative BD was estimated semiautomatically using the thresholding technique Cumulus4. Appropriate statistical tests were used to assess the agreement between the AUQV MR measurements and to compare them with qualitative and quantitative MG BD estimations. The AUQV MR BD measurements were successfully performed in all 43 women. There was a nearly perfect agreement of AUQV MR BD measurements between the 2 MR examinations for % BD (P < 0.001; intraclass correlation coefficient, 0.998) with no significant differences (P = 0.384). The AUQV MR BD measurements were significantly lower than quantitative and qualitative MG BD assessment (P < 0.001). The AUQV MR BD measurement system allows a fully automated, user-independent, robust, reproducible, as well as radiation- and compression-free volumetric quantitative BD assessment through different levels of BD. The AUQV MR BD measurements were significantly lower than the currently used qualitative and quantitative MG-based approaches, implying that the current assessment might overestimate breast density with MG.

Nonlinear dynamic analysis of voices before and after surgical excision of vocal polyps

NASA Astrophysics Data System (ADS)

Zhang, Yu; McGilligan, Clancy; Zhou, Liang; Vig, Mark; Jiang, Jack J.

2004-05-01

Phase space reconstruction, correlation dimension, and second-order entropy, methods from nonlinear dynamics, are used to analyze sustained vowels generated by patients before and after surgical excision of vocal polyps. Two conventional acoustic perturbation parameters, jitter and shimmer, are also employed to analyze voices before and after surgery. Presurgical and postsurgical analyses of jitter, shimmer, correlation dimension, and second-order entropy are statistically compared. Correlation dimension and second-order entropy show a statistically significant decrease after surgery, indicating reduced complexity and higher predictability of postsurgical voice dynamics. There is not a significant postsurgical difference in shimmer, although jitter shows a significant postsurgical decrease. The results suggest that jitter and shimmer should be applied to analyze disordered voices with caution; however, nonlinear dynamic methods may be useful for analyzing abnormal vocal function and quantitatively evaluating the effects of surgical excision of vocal polyps.

A Comparison of Didactic and Inquiry Teaching Methods in a Rural Community College Earth Science Course

NASA Astrophysics Data System (ADS)

Beam, Margery Elizabeth

The combination of increasing enrollment and the importance of providing transfer students a solid foundation in science calls for science faculty to evaluate teaching methods in rural community colleges. The purpose of this study was to examine and compare the effectiveness of two teaching methods, inquiry teaching methods and didactic teaching methods, applied in a rural community college earth science course. Two groups of students were taught the same content via inquiry and didactic teaching methods. Analysis of quantitative data included a non-parametric ranking statistical testing method in which the difference between the rankings and the median of the post-test scores was analyzed for significance. Results indicated there was not a significant statistical difference between the teaching methods for the group of students participating in the research. The practical and educational significance of this study provides valuable perspectives on teaching methods and student learning styles in rural community colleges.

Quantitative evaluation of dual-flip-angle T1 mapping on DCE-MRI kinetic parameter estimation in head and neck

PubMed Central

Chow, Steven Kwok Keung; Yeung, David Ka Wai; Ahuja, Anil T; King, Ann D

2012-01-01

Purpose To quantitatively evaluate the kinetic parameter estimation for head and neck (HN) dynamic contrast-enhanced (DCE) MRI with dual-flip-angle (DFA) T1 mapping. Materials and methods Clinical DCE-MRI datasets of 23 patients with HN tumors were included in this study. T1 maps were generated based on multiple-flip-angle (MFA) method and different DFA combinations. Tofts model parameter maps of kep, Ktrans and vp based on MFA and DFAs were calculated and compared. Fitted parameter by MFA and DFAs were quantitatively evaluated in primary tumor, salivary gland and muscle. Results T1 mapping deviations by DFAs produced remarkable kinetic parameter estimation deviations in head and neck tissues. In particular, the DFA of [2º, 7º] overestimated, while [7º, 12º] and [7º, 15º] underestimated Ktrans and vp, significantly (P<0.01). [2º, 15º] achieved the smallest but still statistically significant overestimation for Ktrans and vp in primary tumors, 32.1% and 16.2% respectively. kep fitting results by DFAs were relatively close to the MFA reference compared to Ktrans and vp. Conclusions T1 deviations induced by DFA could result in significant errors in kinetic parameter estimation, particularly Ktrans and vp, through Tofts model fitting. MFA method should be more reliable and robust for accurate quantitative pharmacokinetic analysis in head and neck. PMID:23289084

The effect of prognostic data presentation format on perceived risk among surrogate decision makers of critically ill patients: a randomized comparative trial.

PubMed

Chapman, Andy R; Litton, Edward; Chamberlain, Jenny; Ho, Kwok M

2015-04-01

The purpose of this study is to determine whether varying the format used to present prognostic data alters the perception of risk among surrogate decision makers in the intensive care unit (ICU). This was a prospective randomized comparative trial conducted in a 23-bed adult tertiary ICU. Enrolled surrogate decision makers were randomized to 1 of 2 questionnaires, which presented hypothetical ICU scenarios, identical other than the format in which prognostic data were presented (eg, frequencies vs percentages). Participants were asked to rate the risk associated with each prognostic statement. We enrolled 141 surrogate decision makers. The perception of risk varied significantly dependent on the presentation format. For "quantitative data," risks were consistently perceived as higher, when presented as frequencies (eg, 1 in 50) compared with equivalent percentages (eg, 2%). Framing "qualitative data" in terms of chance of "death" rather than "survival" led to a statistically significant increase in perceived risks. Framing "quantitative" data in this way did not significantly affect risk perception. Data format had a significant effect on how surrogate decision makers interpreted risk. Qualitative statements are interpreted widely and affected by framing. Where possible, multiple quantitative formats should be used for presenting prognostic information. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

Agreement between calcaneal quantitative ultrasound and osteoporosis self-assessment tool for Asians in identifying individuals at risk of osteoporosis

PubMed Central

Chin, Kok-Yong; Low, Nie Yen; Kamaruddin, Alia Annessa Ain; Dewiputri, Wan Ilma; Soelaiman, Ima-Nirwana

2017-01-01

Background Calcaneal quantitative ultrasound (QUS) is a useful tool in osteoporosis screening. However, QUS device may not be available at all primary health care settings. Osteoporosis self-assessment tool for Asians (OSTA) is a simple algorithm for osteoporosis screening that does not require any sophisticated instruments. This study explored the possibility of replacing QUS with OSTA by determining their agreement in identifying individuals at risk of osteoporosis. Methods A cross-sectional study was conducted to recruit Malaysian men and women aged ≥50 years. Their bone health status was measured using a calcaneal QUS device and OSTA. The association between OSTA and QUS was determined using Spearman’s correlation and their agreement was assessed using Cohen Kappa and receiver-operating curve. Results All QUS indices correlated significantly with OSTA (p<0.05). The agreement between QUS and OSTA was minimal but statistically significant (p<0.05). The performance of OSTA in identifying subjects at risk of osteoporosis according to QUS was poor-to-fair in women (p<0.05), but not statistically significant for men (p>0.05). Changing the cut-off values improved the performance of OSTA in women but not in men. Conclusion The agreement between QUS and OSTA is minimal in categorizing individuals at risk of osteoporosis. Therefore, they cannot be used interchangeably in osteoporosis screening. PMID:29070951

Efficacy of mesotherapy in facial rejuvenation: a histological and immunohistochemical evaluation

PubMed Central

El-Domyati, Moetaz; El-Ammawi, Tarek S.; Moawad, Osama; El-Fakahany, Hasan; Medhat, Walid; Mahoney, Mỹ G.; Uitto, Jouni

2012-01-01

Background Mesotherapy, commonly known as “biorejuvenation” or “biorevitalization”, is a technique used to rejuvenate the skin by means of a transdermal injection of a multivitamin solution and natural plant extracts that are thought to improve the signs of skin aging. Objectives This prospective study aimed to evaluate the clinical effect of mesotherapy applied to periorbital wrinkles and to quantitatively evaluate histological changes in the skin occurring in response to the same treatment. Methods Six volunteers with Fitzpatrick skin types III or IV and Glogau class I–III wrinkles were subjected to a three-month course of mesotherapy injections in the periocular area (six sessions administered at two-week intervals). Standard photographs and skin biopsies were obtained from the treatment area at baseline, at the end of treatment, and at three months post-treatment. Quantitative evaluation of collagen types I, III, and VII, newly synthesized collagen, total elastin, and tropoelastin was performed using a computerized morphometric analysis. Results The clinical evaluation of volunteers at baseline, end of treatment, and three months post-treatment revealed no significant differences. Histological and immunostaining analysis of collagen types I, III, and VII, newly synthesized collagen, total elastin, and tropoelastin showed no statistically significant changes (P > 0.05) after mesotherapy injection. Conclusions The present study indicates that mesotherapy for skin rejuvenation does not result in statistically significant histological changes or clinical improvement. PMID:22788806

Gender, Math Confidence, and Grit: Relationships with Quantitative Skills and Performance in an Undergraduate Biology Course

PubMed Central

Flanagan, K. M.; Einarson, J.

2017-01-01

In a world filled with big data, mathematical models, and statistics, the development of strong quantitative skills is becoming increasingly critical for modern biologists. Teachers in this field must understand how students acquire quantitative skills and explore barriers experienced by students when developing these skills. In this study, we examine the interrelationships among gender, grit, and math confidence for student performance on a pre–post quantitative skills assessment and overall performance in an undergraduate biology course. Here, we show that females significantly underperformed relative to males on a quantitative skills assessment at the start of term. However, females showed significantly higher gains over the semester, such that the gender gap in performance was nearly eliminated by the end of the semester. Math confidence plays an important role in the performance on both the pre and post quantitative skills assessments and overall performance in the course. The effect of grit on student performance, however, is mediated by a student’s math confidence; as math confidence increases, the positive effect of grit decreases. Consequently, the positive impact of a student’s grittiness is observed most strongly for those students with low math confidence. We also found grit to be positively associated with the midterm score and the final grade in the course. Given the relationships established in this study among gender, grit, and math confidence, we provide “instructor actions” from the literature that can be applied in the classroom to promote the development of quantitative skills in light of our findings. PMID:28798209

Meta-analysis of the efficacy and safety of combined surgery in the management of eyes with coexisting cataract and open angle glaucoma.

PubMed

Jiang, Nan; Zhao, Gui-Qiu; Lin, Jing; Hu, Li-Ting; Che, Cheng-Ye; Wang, Qian; Xu, Qiang; Li, Cui; Zhang, Jie

2018-01-01

To conduct a systematic review and quantitative Meta-analysis of the efficacy and safety of combined surgery for the eyes with coexisting cataract and open angle glaucoma. We performed a systematic search of the related literature in the Cochrane Library, PubMed, EMBASE, Web of Science databases, CNKI, CBM and Wan Fang databases, with no limitations on language or publication date. The primary efficacy estimate was identified by weighted mean difference of the percentage of intraocular pressure reduction (IOPR%) from baseline to end-point, the percentage of number of glaucoma medications reduction from pre- to post-operation, and the secondary efficacy evaluations were performed by odds ratio (OR) and 95% confidence interval (CI) for complete and qualified success rate. Besides, ORs were applied to assess the tolerability of adverse incidents. Meta-analyses of fixed or random effect models were performed using RevMan software 5.2 to gather the consequences. Heterogeneity was evaluated by Chi 2 test and the I 2 measure. Ten studies enrolling 3108 patients were included. The combined consequences indicated that both glaucoma and combined cataract and glaucoma surgery significantly decreased IOP. For deep sclerectomy vs deep sclerectomy plus phacoemulsification and canaloplasty vs phaco-canaloplasty, the differences in IOPR% were not all statistically significant while trabeculotomy was detected to gain a quantitatively greater IOPR% compared with trabeculotomy plus phacoemulsification. Furthermore, there was no statistical significance in the complete and qualified success rate, and the rates of adverse incidents for trabeculotomy vs trabeculotomy plus phacoemulsification. Compared with trabeculotomy plus phacoemulsification, trabeculectomy alone is more effective in lowering IOP and the number of glaucoma medications, while the two surgeries can not demonstrate statistical differences in the complete success rate, qualified success rate, or incidence of adverse incidents.

A Quantitative Study of Empathy in Pakistani Medical Students: A Multicentered Approach.

PubMed

Tariq, Nabia; Rasheed, Tariq; Tavakol, Mohsen

2017-10-01

To examine the empathy level of undergraduate medical students in Pakistan. Three hypotheses are developed based on the literature review. (1) Female medical students have a higher level of empathy than do male students. (2) Empathy scores vary during the medical school years in Pakistani students. (3) Medical students interested in people-oriented specialties would score higher than the students interested in technology-oriented specialties. This is a quantitative inquiry approach using a cross-sectional design of 1453 students from 8 Pakistani medical schools, both private and state. The sample consists of 41.1% (n = 597) male students and 58.9% (n = 856) female students. Empirical data are collected using the Jefferson Scale of Physician Empathy (JSPE), a well-validated self-administered questionnaire. The mean empathy score among students is 4.77 with a standard deviation of 0.72. The results show that there is no statistically significant association between the empathy scores and gender, t(1342.36) = -0.053, P = .95). There is a statistically significant difference between the empathy scores and the years of medical school, F(14, 1448) = 4.95, P = .01. Concerning the specialty interests, there is no statistically significant difference between the empathy score and specialty interests. The findings of this study showed that in Western countries, medical students performed better than Pakistani medical students on the empathy scale. This finding has important implications for Pakistani medical educators to improve the interpersonal skills of medical students in the context of patient care. Inconsistent with our expectations and experiences, our findings do not support that female medical students scored better than their male counterparts on the empathy scale. Because of the nature of a cross-sectional study, it is impossible to argue the decline of empathy during medical school training.

Quantitative characterization of genetic parts and circuits for plant synthetic biology.

PubMed

Schaumberg, Katherine A; Antunes, Mauricio S; Kassaw, Tessema K; Xu, Wenlong; Zalewski, Christopher S; Medford, June I; Prasad, Ashok

2016-01-01

Plant synthetic biology promises immense technological benefits, including the potential development of a sustainable bio-based economy through the predictive design of synthetic gene circuits. Such circuits are built from quantitatively characterized genetic parts; however, this characterization is a significant obstacle in work with plants because of the time required for stable transformation. We describe a method for rapid quantitative characterization of genetic plant parts using transient expression in protoplasts and dual luciferase outputs. We observed experimental variability in transient-expression assays and developed a mathematical model to describe, as well as statistical normalization methods to account for, this variability, which allowed us to extract quantitative parameters. We characterized >120 synthetic parts in Arabidopsis and validated our method by comparing transient expression with expression in stably transformed plants. We also tested >100 synthetic parts in sorghum (Sorghum bicolor) protoplasts, and the results showed that our method works in diverse plant groups. Our approach enables the construction of tunable gene circuits in complex eukaryotic organisms.

Descriptive statistics.

PubMed

Nick, Todd G

2007-01-01

Statistics is defined by the Medical Subject Headings (MeSH) thesaurus as the science and art of collecting, summarizing, and analyzing data that are subject to random variation. The two broad categories of summarizing and analyzing data are referred to as descriptive and inferential statistics. This chapter considers the science and art of summarizing data where descriptive statistics and graphics are used to display data. In this chapter, we discuss the fundamentals of descriptive statistics, including describing qualitative and quantitative variables. For describing quantitative variables, measures of location and spread, for example the standard deviation, are presented along with graphical presentations. We also discuss distributions of statistics, for example the variance, as well as the use of transformations. The concepts in this chapter are useful for uncovering patterns within the data and for effectively presenting the results of a project.

Use of statistical and neural net approaches in predicting toxicity of chemicals.

PubMed

Basak, S C; Grunwald, G D; Gute, B D; Balasubramanian, K; Opitz, D

2000-01-01

Hierarchical quantitative structure-activity relationships (H-QSAR) have been developed as a new approach in constructing models for estimating physicochemical, biomedicinal, and toxicological properties of interest. This approach uses increasingly more complex molecular descriptors in a graduated approach to model building. In this study, statistical and neural network methods have been applied to the development of H-QSAR models for estimating the acute aquatic toxicity (LC50) of 69 benzene derivatives to Pimephales promelas (fathead minnow). Topostructural, topochemical, geometrical, and quantum chemical indices were used as the four levels of the hierarchical method. It is clear from both the statistical and neural network models that topostructural indices alone cannot adequately model this set of congeneric chemicals. Not surprisingly, topochemical indices greatly increase the predictive power of both statistical and neural network models. Quantum chemical indices also add significantly to the modeling of this set of acute aquatic toxicity data.

Leadership and Culture-Building in Schools: Quantitative and Qualitative Understandings.

ERIC Educational Resources Information Center

Sashkin, Marshall; Sashkin, Molly G.

Understanding effective school leadership as a function of culture building through quantitative and qualitative analyses is the purpose of this paper. The two-part quantitative phase of the research focused on statistical measures of culture and leadership behavior directed toward culture building in the school. The first quantitative part…

Visually estimated ejection fraction by two dimensional and triplane echocardiography is closely correlated with quantitative ejection fraction by real-time three dimensional echocardiography

PubMed Central

Shahgaldi, Kambiz; Gudmundsson, Petri; Manouras, Aristomenis; Brodin, Lars-Åke; Winter, Reidar

2009-01-01

Background Visual assessment of left ventricular ejection fraction (LVEF) is often used in clinical routine despite general recommendations to use quantitative biplane Simpsons (BPS) measurements. Even thou quantitative methods are well validated and from many reasons preferable, the feasibility of visual assessment (eyeballing) is superior. There is to date only sparse data comparing visual EF assessment in comparison to quantitative methods available. The aim of this study was to compare visual EF assessment by two-dimensional echocardiography (2DE) and triplane echocardiography (TPE) using quantitative real-time three-dimensional echocardiography (RT3DE) as the reference method. Methods Thirty patients were enrolled in the study. Eyeballing EF was assessed using apical 4-and 2 chamber views and TP mode by two experienced readers blinded to all clinical data. The measurements were compared to quantitative RT3DE. Results There were an excellent correlation between eyeballing EF by 2D and TP vs 3DE (r = 0.91 and 0.95 respectively) without any significant bias (-0.5 ± 3.7% and -0.2 ± 2.9% respectively). Intraobserver variability was 3.8% for eyeballing 2DE, 3.2% for eyeballing TP and 2.3% for quantitative 3D-EF. Interobserver variability was 7.5% for eyeballing 2D and 8.4% for eyeballing TP. Conclusion Visual estimation of LVEF both using 2D and TP by an experienced reader correlates well with quantitative EF determined by RT3DE. There is an apparent trend towards a smaller variability using TP in comparison to 2D, this was however not statistically significant. PMID:19706183

Improving validation methods for molecular diagnostics: application of Bland-Altman, Deming and simple linear regression analyses in assay comparison and evaluation for next-generation sequencing

PubMed Central

Misyura, Maksym; Sukhai, Mahadeo A; Kulasignam, Vathany; Zhang, Tong; Kamel-Reid, Suzanne; Stockley, Tracy L

2018-01-01

Aims A standard approach in test evaluation is to compare results of the assay in validation to results from previously validated methods. For quantitative molecular diagnostic assays, comparison of test values is often performed using simple linear regression and the coefficient of determination (R2), using R2 as the primary metric of assay agreement. However, the use of R2 alone does not adequately quantify constant or proportional errors required for optimal test evaluation. More extensive statistical approaches, such as Bland-Altman and expanded interpretation of linear regression methods, can be used to more thoroughly compare data from quantitative molecular assays. Methods We present the application of Bland-Altman and linear regression statistical methods to evaluate quantitative outputs from next-generation sequencing assays (NGS). NGS-derived data sets from assay validation experiments were used to demonstrate the utility of the statistical methods. Results Both Bland-Altman and linear regression were able to detect the presence and magnitude of constant and proportional error in quantitative values of NGS data. Deming linear regression was used in the context of assay comparison studies, while simple linear regression was used to analyse serial dilution data. Bland-Altman statistical approach was also adapted to quantify assay accuracy, including constant and proportional errors, and precision where theoretical and empirical values were known. Conclusions The complementary application of the statistical methods described in this manuscript enables more extensive evaluation of performance characteristics of quantitative molecular assays, prior to implementation in the clinical molecular laboratory. PMID:28747393

A Content Analysis of Quantitative Research in Journal of Marital and Family Therapy: A 10-Year Review.

PubMed

Parker, Elizabeth O; Chang, Jennifer; Thomas, Volker

2016-01-01

We examined the trends of quantitative research over the past 10 years in the Journal of Marital and Family Therapy (JMFT). Specifically, within the JMFT, we investigated the types and trends of research design and statistical analysis within the quantitative research that was published in JMFT from 2005 to 2014. We found that while the amount of peer-reviewed articles have increased over time, the percentage of quantitative research has remained constant. We discussed the types and trends of statistical analysis and the implications for clinical work and training programs in the field of marriage and family therapy. © 2016 American Association for Marriage and Family Therapy.

Modelling the effect of structural QSAR parameters on skin penetration using genetic programming

NASA Astrophysics Data System (ADS)

Chung, K. K.; Do, D. Q.

2010-09-01

In order to model relationships between chemical structures and biological effects in quantitative structure-activity relationship (QSAR) data, an alternative technique of artificial intelligence computing—genetic programming (GP)—was investigated and compared to the traditional method—statistical. GP, with the primary advantage of generating mathematical equations, was employed to model QSAR data and to define the most important molecular descriptions in QSAR data. The models predicted by GP agreed with the statistical results, and the most predictive models of GP were significantly improved when compared to the statistical models using ANOVA. Recently, artificial intelligence techniques have been applied widely to analyse QSAR data. With the capability of generating mathematical equations, GP can be considered as an effective and efficient method for modelling QSAR data.

Investigating the Pedagogical Approaches Related to Changes in Attitudes toward Statistics in a Quantitative Methods Course for Psychology Undergraduate Students

ERIC Educational Resources Information Center

Liau, Albert K.; Kiat, John E.; Nie, Youyan

2015-01-01

The purpose of this study was to examine the extent to which the pedagogical approaches used in the course were related to improvements in students' attitudes toward statistics in a Quantitative Methods course for psychology undergraduate students in a Malaysian University. The study examined whether increasing availability of the instructor and…

Quantitative analysis of macrophages in wound healing of rat skin subjected to loud noise stress.

PubMed

Rafi, Aisha; Khan, Muhammad Yunus; Minhas, Liaqat Ali

2014-01-01

Factors affecting skin wound healing have always been a central consideration in medical practice. Loud noise is biological stressor affecting the body systems at various levels. The present study was taken to study the effect of loud noise stress on the macrophages during wound healing process in male rat skin. One hundred and eighty male Sprague Dawley rats were randomly divided into control group-A and experimental group-B. Each group comprised 90 animals. Control and experimental groups were further subdivided into three subgroups of 30 animals each, corresponding to the day of sacrifice of animals, i.e., day 3, 5 and 7 after surgery. After induction of local anaesthesia a linear full thickness incision paravertebral to thoracic spine was made on the dorsum of rat. The experimental group B was exposed to loud noise stimulus (recorded noise of aero planes and gun fire) set at 97dBA to 102 dBA with a sound level meter. The animals were decapitated on day 3, 5 and 7 after surgery. Tissue was processed for paraffin embedding and stained by Hematoxylin and Eosin and Mallory's trichrome stain. Data was collected for the incisional space of the wound. Quantitative data of number of macrophages was analysed by Student's' test for the detection of any significant differences between the mean number in the experimental and control groups. All the quantitative data was expressed as means ± SE. A p-value of ≤ 0.05 was considered statistically significant. In this study macrophages were decreased statistically significantly at day 3 after surgery and thereafter increased significantly on day 5 and 7 after surgery in the experimental subgroups as compared to their match control subgroups. These results show that loud noise stress affects the cells (macrophages) involved in the healing of the wound therefore it is expected to have impact on the stages of wound healing.

Alar-columellar and lateral nostril changes following tongue-in-groove rhinoplasty.

PubMed

Shah, Ajul; Pfaff, Miles; Kinsman, Gianna; Steinbacher, Derek M

2015-04-01

Repositioning the medial crura cephalically onto the caudal septum (tongue-in-groove; TIG) allows alteration of the columella, ala, and nasal tip to address alar-columellar disproportion as seen from the lateral view. To date, quantitative analysis of nostril dimension, alar-columellar relationship, and nasal tip changes following the TIG rhinoplasty technique have not been described. The present study aims to evaluate post-operative lateral morphometric changes following TIG. Pre- and post-operative lateral views of a series of consecutive patients who underwent TIG rhinoplasty were produced from 3D images at multiple time points (≤2 weeks, 4-10 weeks, and >10 weeks post-operatively) for analysis. The 3D images were converted to 2D and set to scale. Exposed lateral nostril area, alar-columellar disproportion (divided into superior and inferior heights), nasolabial angle, nostril height, and nostril length were calculated and statistically analyzed using a pairwise t test. A P ≤ 0.05 was considered statistically significant. Ninety-four lateral views were analyzed from 20 patients (16 females; median age: 31.8). One patient had a history of current tobacco cigarette use. Lateral nostril area decreased at all time points post-operatively, in a statistically significant fashion. Alar-columellar disproportion was reduced following TIG at all time points. The nasolabial angle significantly increased post-operatively at ≤2 weeks, 4-10 weeks, and >10, all in a statistically significant fashion. Nostril height and nostril length decreased at all post-operative time points. Morphometric analysis reveals reduction in alar-columellar disproportion and lateral nostril shows following TIG rhinoplasty. Tip rotation, as a function of nasolabial angle, also increased. These results provide quantitative substantiation for qualitative descriptions attributed to the TIG technique. Future studies will focus on area and volumetric measurements, and assessment of long-term stability. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Clinical significance in nursing research: A discussion and descriptive analysis.

PubMed

Polit, Denise F

2017-08-01

It is widely understood that statistical significance should not be equated with clinical significance, but the topic of clinical significance has not received much attention in the nursing literature. By contrast, interest in conceptualizing and operationalizing clinical significance has been a "hot topic" in other health care fields for several decades. The major purpose of this paper is to briefly describe recent advances in defining and quantifying clinical significance. The overview covers both group-level indicators of clinical significance (e.g., effect size indexes), and individual-level benchmarks (e.g., the minimal important change index). A secondary purpose is to describe the extent to which developments in clinical significance have penetrated the nursing literature. A descriptive analysis of a sample of primary research articles published in three high-impact nursing research journals in 2016 was undertaken. A total of 362 articles were electronically searched for terms relating to statistical and clinical significance. Of the 362 articles, 261 were reports of quantitative studies, the vast majority of which (93%) included a formal evaluation of the statistical significance of the results. By contrast, the term "clinical significance" or related surrogate terms were found in only 33 papers, and most often the term was used informally, without explicit definition or assessment. Raising consciousness about clinical significance should be an important priority among nurse researchers. Several recommendations are offered to improve the visibility and salience of clinical significance in nursing science. Copyright © 2017 Elsevier Ltd. All rights reserved.

Regenerate Healing Outcomes in Unilateral Mandibular Distraction Osteogenesis Using Quantitative Histomorphometry

PubMed Central

Schwarz, Daniel A.; Arman, Krikor G.; Kakwan, Mehreen S.; Jamali, Ameen M.; Elmeligy, Ayman A.; Buchman, Steven R.

2015-01-01

Background The authors’ goal was to ascertain regenerate bone-healing metrics using quantitative histomorphometry at a single consolidation period. Methods Rats underwent either mandibular distraction osteogenesis (n=7) or partially reduced fractures (n=7); their contralateral mandibles were used as controls (n=11). External fixators were secured and unilateral osteotomies performed, followed by either mandibular distraction osteogenesis (4 days’ latency, then 0.3 mm every 12 hours for 8 days; 5.1 mm) or partially reduced fractures (fixed immediately postoperatively; 2.1 mm); both groups underwent 4 weeks of consolidation. After tissue processing, bone volume/tissue volume ratio, osteoid volume/tissue volume ratio, and osteocyte count per high-power field were analyzed by means of quantitative histomorphometry. Results Contralateral mandibles had statistically greater bone volume/tissue volume ratio and osteocyte count per high-power field compared with both mandibular distraction osteogenesis and partially reduced fractures by almost 50 percent, whereas osteoid volume/tissue volume ratio was statistically greater in both mandibular distraction osteogenesis specimens and partially reduced fractures compared with contralateral mandibles. No statistical difference in bone volume/tissue volume ratio, osteoid volume/tissue volume ratio, or osteocyte count per high-power field was found between mandibular distraction osteogenesis specimens and partially reduced fractures. Conclusions The authors’ findings demonstrate significantly decreased bone quantity and maturity in mandibular distraction osteogenesis specimens and partially reduced fractures compared with contralateral mandibles using the clinically analogous protocols. If these results are extrapolated clinically, treatment strategies may require modification to ensure reliable, predictable, and improved outcomes. PMID:20463629

Functional quantitative susceptibility mapping (fQSM).

PubMed

Balla, Dávid Z; Sanchez-Panchuelo, Rosa M; Wharton, Samuel J; Hagberg, Gisela E; Scheffler, Klaus; Francis, Susan T; Bowtell, Richard

2014-10-15

Blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) is a powerful technique, typically based on the statistical analysis of the magnitude component of the complex time-series. Here, we additionally interrogated the phase data of the fMRI time-series and used quantitative susceptibility mapping (QSM) in order to investigate the potential of functional QSM (fQSM) relative to standard magnitude BOLD fMRI. High spatial resolution data (1mm isotropic) were acquired every 3 seconds using zoomed multi-slice gradient-echo EPI collected at 7 T in single orientation (SO) and multiple orientation (MO) experiments, the latter involving 4 repetitions with the subject's head rotated relative to B0. Statistical parametric maps (SPM) were reconstructed for magnitude, phase and QSM time-series and each was subjected to detailed analysis. Several fQSM pipelines were evaluated and compared based on the relative number of voxels that were coincidentally found to be significant in QSM and magnitude SPMs (common voxels). We found that sensitivity and spatial reliability of fQSM relative to the magnitude data depended strongly on the arbitrary significance threshold defining "activated" voxels in SPMs, and on the efficiency of spatio-temporal filtering of the phase time-series. Sensitivity and spatial reliability depended slightly on whether MO or SO fQSM was performed and on the QSM calculation approach used for SO data. Our results present the potential of fQSM as a quantitative method of mapping BOLD changes. We also critically discuss the technical challenges and issues linked to this intriguing new technique. Copyright © 2014 Elsevier Inc. All rights reserved.

In vitro adherence of radioactively labeled Escherichia coli in normal and cystitis-prone females

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

Parsons, C.L.; Anwar, H.; Stauffer, C.

Numerous investigators report data obtained using an in vitro quantitative assay for measuring bacterial adherence to epithelial cells. In the modified assay described here, we eliminated the need for visual counting of bacteria by incorporating the use of radioactively labeled Escherichia coli. This allowed quantitation of bacterial adherence to as many as 50,000 vaginal cells, whereas the visual counting system limits the determination to perhaps 50 cells. Using the modified method, we found no statistically significant differences among values for adherence of E. coli type 04 to the vaginal cells of control and cystitis-prone women at either pH 6.4 ormore » 4.0.« less

Optical spectroscopy for quantitative sensing in human pancreatic tissues

NASA Astrophysics Data System (ADS)

Wilson, Robert H.; Chandra, Malavika; Lloyd, William; Chen, Leng-Chun; Scheiman, James; Simeone, Diane; McKenna, Barbara; Mycek, Mary-Ann

2011-07-01

Pancreatic adenocarcinoma has a five-year survival rate of only 6%, largely because current diagnostic methods cannot reliably detect the disease in its early stages. Reflectance and fluorescence spectroscopies have the potential to provide quantitative, minimally-invasive means of distinguishing pancreatic adenocarcinoma from normal pancreatic tissue and chronic pancreatitis. The first collection of wavelength-resolved reflectance and fluorescence spectra and time-resolved fluorescence decay curves from human pancreatic tissues was acquired with clinically-compatible instrumentation. Mathematical models of reflectance and fluorescence extracted parameters related to tissue morphology and biochemistry that were statistically significant for distinguishing between pancreatic tissue types. These results suggest that optical spectroscopy has the potential to detect pancreatic disease in a clinical setting.

[Comparative analysis of real-time quantitative PCR-Sanger sequencing method and TaqMan probe method for detection of KRAS/BRAF mutation in colorectal carcinomas].

PubMed

Zhang, Xun; Wang, Yuehua; Gao, Ning; Wang, Jinfen

2014-02-01

To compare the application values of real-time quantitative PCR-Sanger sequencing and TaqMan probe method in the detection of KRAS and BRAF mutations, and to correlate KRAS/BRAF mutations with the clinicopathological characteristics in colorectal carcinomas. Genomic DNA of the tumor cells was extracted from formalin fixed paraffin embedded (FFPE) tissue samples of 344 colorectal carcinomas by microdissection. Real-time quantitative PCR-Sanger sequencing and TaqMan probe method were performed to detect the KRAS/BRAF mutations. The frequency and types of KRAS/BRAF mutations, clinicopathological characteristics and survival time were analyzed. KRAS mutations were detected in 39.8% (137/344) and 38.7% (133/344) of 344 colorectal carcinomas by using real-time quantitative PCR-Sanger sequencing and TaqMan probe method, respectively. BRAF mutation was detected in 4.7% (16/344) and 4.1% (14/344), respectively. There was no significant correlation between the two methods. The frequency of the KRAS mutation in female was higher than that in male (P < 0.05). The frequency of the BRAF mutation in colon was higher than that in rectum. The frequency of the BRAF mutation in stage III-IV cases was higher than that in stageI-II cases. The frequency of the BRAF mutation in signet ring cell carcinoma was higher than that in mucinous carcinoma and nonspecific adenocarcinoma had the lowest mutation rate. The frequency of the BRAF mutation in grade III cases was higher than that in grade II cases (P < 0.05). The overall concordance for the two methods of KRAS/BRAF mutation detection was 98.8% (kappa = 0.976). There was statistic significance between BRAF and KRAS mutations for the survival time of colorectal carcinomas (P = 0.039). There were no statistic significance between BRAF mutation type and BRAF/KRAS wild type (P = 0.058). (1) Compared with real-time quantitative PCR-Sanger sequencing, TaqMan probe method is better with regard to handling time, efficiency, repeatability, cost and equipment. (2) The frequency of the KRAS mutation is correlated with gender. BRAF mutation is correlated with primary tumor site, TNM stage, histological types and histological grades.(3) BRAF gene mutation is an independent prognostic marker for colorectal carcinomas.

Mapping morphological shape as a high-dimensional functional curve

PubMed Central

Fu, Guifang; Huang, Mian; Bo, Wenhao; Hao, Han; Wu, Rongling

2018-01-01

Abstract Detecting how genes regulate biological shape has become a multidisciplinary research interest because of its wide application in many disciplines. Despite its fundamental importance, the challenges of accurately extracting information from an image, statistically modeling the high-dimensional shape and meticulously locating shape quantitative trait loci (QTL) affect the progress of this research. In this article, we propose a novel integrated framework that incorporates shape analysis, statistical curve modeling and genetic mapping to detect significant QTLs regulating variation of biological shape traits. After quantifying morphological shape via a radius centroid contour approach, each shape, as a phenotype, was characterized as a high-dimensional curve, varying as angle θ runs clockwise with the first point starting from angle zero. We then modeled the dynamic trajectories of three mean curves and variation patterns as functions of θ. Our framework led to the detection of a few significant QTLs regulating the variation of leaf shape collected from a natural population of poplar, Populus szechuanica var tibetica. This population, distributed at altitudes 2000–4500 m above sea level, is an evolutionarily important plant species. This is the first work in the quantitative genetic shape mapping area that emphasizes a sense of ‘function’ instead of decomposing the shape into a few discrete principal components, as the majority of shape studies do. PMID:28062411

Findings from a study of aspiring nursing student leaders.

PubMed

Waite, Roberta; McKinney, Nicole S

2015-12-01

Transformational leadership skills are critical to operate effectively in today's healthcare environment. Prelicensure nurses do not often practice these skills in a meaningful way during their undergraduate educational experience. This paper describes quantitative pre-post findings from the Kouzes and Posner Student Leadership Practices Inventory to examine students' leadership attributes pre-post engagement in an 18 month undergraduate leadership program. This is a non-experimental convenience study that used a quantitative pre-post survey design collecting data from participants and observers using the 360 Kouzes and Posner Student Leadership Practices Inventory. A private university in the northeastern region of the United States. Fourteen junior level nursing students who concurrently participated in a leadership program while concurrently completing their required academic courses for their bachelor's degree in nursing. Paired sample t-tests were used to determine if there was statistical significance among student participants' and observers' perceptions of specific leadership behaviors and skills of students at the onset (pretest) and at the conclusion (posttest) of the leadership program. Participant and observer scores were positively correlated and statistical significance was identified in several practice areas. It is important to integrate transformation leadership skills into undergraduate curriculum since it supports students' engagement in their own learning and instills foundational knowledge critical to their leadership trajectory. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Generalized Approach for the Interpretation of Geophysical Well Logs in Ground-Water Studies - Theory and Application

USGS Publications Warehouse

Paillet, Frederick L.; Crowder, R.E.

1996-01-01

Quantitative analysis of geophysical logs in ground-water studies often involves at least as broad a range of applications and variation in lithology as is typically encountered in petroleum exploration, making such logs difficult to calibrate and complicating inversion problem formulation. At the same time, data inversion and analysis depend on inversion model formulation and refinement, so that log interpretation cannot be deferred to a geophysical log specialist unless active involvement with interpretation can be maintained by such an expert over the lifetime of the project. We propose a generalized log-interpretation procedure designed to guide hydrogeologists in the interpretation of geophysical logs, and in the integration of log data into ground-water models that may be systematically refined and improved in an iterative way. The procedure is designed to maximize the effective use of three primary contributions from geophysical logs: (1) The continuous depth scale of the measurements along the well bore; (2) The in situ measurement of lithologic properties and the correlation with hydraulic properties of the formations over a finite sample volume; and (3) Multiple independent measurements that can potentially be inverted for multiple physical or hydraulic properties of interest. The approach is formulated in the context of geophysical inversion theory, and is designed to be interfaced with surface geophysical soundings and conventional hydraulic testing. The step-by-step procedures given in our generalized interpretation and inversion technique are based on both qualitative analysis designed to assist formulation of the interpretation model, and quantitative analysis used to assign numerical values to model parameters. The approach bases a decision as to whether quantitative inversion is statistically warranted by formulating an over-determined inversion. If no such inversion is consistent with the inversion model, quantitative inversion is judged not possible with the given data set. Additional statistical criteria such as the statistical significance of regressions are used to guide the subsequent calibration of geophysical data in terms of hydraulic variables in those situations where quantitative data inversion is considered appropriate.

Quantitative analysis of aircraft multispectral-scanner data and mapping of water-quality parameters in the James River in Virginia

NASA Technical Reports Server (NTRS)

Johnson, R. W.; Bahn, G. S.

1977-01-01

Statistical analysis techniques were applied to develop quantitative relationships between in situ river measurements and the remotely sensed data that were obtained over the James River in Virginia on 28 May 1974. The remotely sensed data were collected with a multispectral scanner and with photographs taken from an aircraft platform. Concentration differences among water quality parameters such as suspended sediment, chlorophyll a, and nutrients indicated significant spectral variations. Calibrated equations from the multiple regression analysis were used to develop maps that indicated the quantitative distributions of water quality parameters and the dispersion characteristics of a pollutant plume entering the turbid river system. Results from further analyses that use only three preselected multispectral scanner bands of data indicated that regression coefficients and standard errors of estimate were not appreciably degraded compared with results from the 10-band analysis.

To be seen or to hide: visual characteristics of body patterns for camouflage and communication in the Australian giant cuttlefish Sepia apama.

PubMed

Zylinski, S; How, M J; Osorio, D; Hanlon, R T; Marshall, N J

2011-05-01

It might seem obvious that a camouflaged animal must generally match its background whereas to be conspicuous an organism must differ from the background. However, the image parameters (or statistics) that evaluate the conspicuousness of patterns and textures are seldom well defined, and animal coloration patterns are rarely compared quantitatively with their respective backgrounds. Here we examine this issue in the Australian giant cuttlefish Sepia apama. We confine our analysis to the best-known and simplest image statistic, the correlation in intensity between neighboring pixels. Sepia apama can rapidly change their body patterns from assumed conspicuous signaling to assumed camouflage, thus providing an excellent and unique opportunity to investigate how such patterns differ in a single visual habitat. We describe the intensity variance and spatial frequency power spectra of these differing body patterns and compare these patterns with the backgrounds against which they are viewed. The measured image statistics of camouflaged animals closely resemble their backgrounds, while signaling animals differ significantly from their backgrounds. Our findings may provide the basis for a set of general rules for crypsis and signals. Furthermore, our methods may be widely applicable to the quantitative study of animal coloration.

Detection of proximal caries using quantitative light-induced fluorescence-digital and laser fluorescence: a comparative study.

PubMed

Yoon, Hyung-In; Yoo, Min-Jeong; Park, Eun-Jin

2017-12-01

The purpose of this study was to evaluate the in vitro validity of quantitative light-induced fluorescence-digital (QLF-D) and laser fluorescence (DIAGNOdent) for assessing proximal caries in extracted premolars, using digital radiography as reference method. A total of 102 extracted premolars with similar lengths and shapes were used. A single operator conducted all the examinations using three different detection methods (bitewing radiography, QLF-D, and DIAGNOdent). The bitewing x-ray scale, QLF-D fluorescence loss (ΔF), and DIAGNOdent peak readings were compared and statistically analyzed. Each method showed an excellent reliability. The correlation coefficient between bitewing radiography and QLF-D, DIAGNOdent were -0.644 and 0.448, respectively, while the value between QLF-D and DIAGNOdent was -0.382. The kappa statistics for bitewing radiography and QLF-D had a higher diagnosis consensus than those for bitewing radiography and DIAGNOdent. The QLF-D was moderately to highly accurate (AUC = 0.753 - 0.908), while DIAGNOdent was moderately to less accurate (AUC = 0.622 - 0.784). All detection methods showed statistically significant correlation and high correlation between the bitewing radiography and QLF-D. QLF-D was found to be a valid and reliable alternative diagnostic method to digital bitewing radiography for in vitro detection of proximal caries.

Quantitative assessment of the effectiveness of phase 1 orthodontic treatment using the American Board of Orthodontics Discrepancy Index.

PubMed

Vasilakou, Nefeli; Araujo, Eustaquio A; Kim, Ki Beom; Oliver, Donald R

2016-12-01

This retrospective study included a sample of 300 randomly selected patients from the archived records of Saint Louis University's graduate orthodontic clinic, St. Louis, Mo, from 1990 to 2012. The objective of this study was to quantify the changes obtained in phase 1 of orthodontic treatment and determine how much improvement, if any, has occurred before the initiation of the second phase. For the purpose of this study, prephase 1 and prephase 2 records of 300 subjects were gathered. All were measured using the American Board of Ortodontics Discrepancy Index (DI), and a score was given for each phase. The difference of the 2 scores indicated the quantitative change of the complexity of the treatment. Paired t tests were used to compare the scores. Additionally, the sample was categorized into 3 groups according to the Angle classifications, and the same statistics were used to identify significant changes between the 2 scores. Analysis of variance was applied to compare the 3 groups and determine which had the most change. Percentages of change were calculated for the significant scores. The total DI score overall and the scores of all 3 groups were significantly reduced from before to after phase 1. Overall, 42% improvement was observed. The Class I group showed 49.3% improvement, the Class II group 34.5% and the Class III group 58.5%. Most components of the DI improved significantly, but a few showed negative changes. Significant reductions of DI scores were observed in the total sample and in all Angle classification groups. This indicates that early treatment reduces the complexity of the malocclusions. Only 2 components of the DI showed statistically significant negative changes. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Quantitative trait nucleotide analysis using Bayesian model selection.

PubMed

Blangero, John; Goring, Harald H H; Kent, Jack W; Williams, Jeff T; Peterson, Charles P; Almasy, Laura; Dyer, Thomas D

2005-10-01

Although much attention has been given to statistical genetic methods for the initial localization and fine mapping of quantitative trait loci (QTLs), little methodological work has been done to date on the problem of statistically identifying the most likely functional polymorphisms using sequence data. In this paper we provide a general statistical genetic framework, called Bayesian quantitative trait nucleotide (BQTN) analysis, for assessing the likely functional status of genetic variants. The approach requires the initial enumeration of all genetic variants in a set of resequenced individuals. These polymorphisms are then typed in a large number of individuals (potentially in families), and marker variation is related to quantitative phenotypic variation using Bayesian model selection and averaging. For each sequence variant a posterior probability of effect is obtained and can be used to prioritize additional molecular functional experiments. An example of this quantitative nucleotide analysis is provided using the GAW12 simulated data. The results show that the BQTN method may be useful for choosing the most likely functional variants within a gene (or set of genes). We also include instructions on how to use our computer program, SOLAR, for association analysis and BQTN analysis.

A GATE evaluation of the sources of error in quantitative {sup 90}Y PET

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

Strydhorst, Jared, E-mail: jared.strydhorst@gmail.

Purpose: Accurate reconstruction of the dose delivered by {sup 90}Y microspheres using a postembolization PET scan would permit the establishment of more accurate dose–response relationships for treatment of hepatocellular carcinoma with {sup 90}Y. However, the quality of the PET data obtained is compromised by several factors, including poor count statistics and a very high random fraction. This work uses Monte Carlo simulations to investigate what impact factors other than low count statistics have on the quantification of {sup 90}Y PET. Methods: PET acquisitions of two phantoms—a NEMA PET phantom and the NEMA IEC PET body phantom-containing either {sup 90}Y ormore » {sup 18}F were simulated using GATE. Simulated projections were created with subsets of the simulation data allowing the contributions of random, scatter, and LSO background to be independently evaluated. The simulated projections were reconstructed using the commercial software for the simulated scanner, and the quantitative accuracy of the reconstruction and the contrast recovery of the reconstructed images were evaluated. Results: The quantitative accuracy of the {sup 90}Y reconstructions were not strongly influenced by the high random fraction present in the projection data, and the activity concentration was recovered to within 5% of the known value. The contrast recovery measured for simulated {sup 90}Y data was slightly poorer than that for simulated {sup 18}F data with similar count statistics. However, the degradation was not strongly linked to any particular factor. Using a more restricted energy range to reduce the random fraction in the projections had no significant effect. Conclusions: Simulations of {sup 90}Y PET confirm that quantitative {sup 90}Y is achievable with the same approach as that used for {sup 18}F, and that there is likely very little margin for improvement by attempting to model aspects unique to {sup 90}Y, such as the much higher random fraction or the presence of bremsstrahlung in the singles data.« less

Validation of Simple Quantification Methods for (18)F-FP-CIT PET Using Automatic Delineation of Volumes of Interest Based on Statistical Probabilistic Anatomical Mapping and Isocontour Margin Setting.

PubMed

Kim, Yong-Il; Im, Hyung-Jun; Paeng, Jin Chul; Lee, Jae Sung; Eo, Jae Seon; Kim, Dong Hyun; Kim, Euishin E; Kang, Keon Wook; Chung, June-Key; Lee, Dong Soo

2012-12-01

(18)F-FP-CIT positron emission tomography (PET) is an effective imaging for dopamine transporters. In usual clinical practice, (18)F-FP-CIT PET is analyzed visually or quantified using manual delineation of a volume of interest (VOI) for the striatum. In this study, we suggested and validated two simple quantitative methods based on automatic VOI delineation using statistical probabilistic anatomical mapping (SPAM) and isocontour margin setting. Seventy-five (18)F-FP-CIT PET images acquired in routine clinical practice were used for this study. A study-specific image template was made and the subject images were normalized to the template. Afterwards, uptakes in the striatal regions and cerebellum were quantified using probabilistic VOI based on SPAM. A quantitative parameter, QSPAM, was calculated to simulate binding potential. Additionally, the functional volume of each striatal region and its uptake were measured in automatically delineated VOI using isocontour margin setting. Uptake-volume product (QUVP) was calculated for each striatal region. QSPAM and QUVP were compared with visual grading and the influence of cerebral atrophy on the measurements was tested. Image analyses were successful in all the cases. Both the QSPAM and QUVP were significantly different according to visual grading (P < 0.001). The agreements of QUVP or QSPAM with visual grading were slight to fair for the caudate nucleus (κ = 0.421 and 0.291, respectively) and good to perfect to the putamen (κ = 0.663 and 0.607, respectively). Also, QSPAM and QUVP had a significant correlation with each other (P < 0.001). Cerebral atrophy made a significant difference in QSPAM and QUVP of the caudate nuclei regions with decreased (18)F-FP-CIT uptake. Simple quantitative measurements of QSPAM and QUVP showed acceptable agreement with visual grading. Although QSPAM in some group may be influenced by cerebral atrophy, these simple methods are expected to be effective in the quantitative analysis of (18)F-FP-CIT PET in usual clinical practice.

Assessment and improvement of statistical tools for comparative proteomics analysis of sparse data sets with few experimental replicates.

PubMed

Schwämmle, Veit; León, Ileana Rodríguez; Jensen, Ole Nørregaard

2013-09-06

Large-scale quantitative analyses of biological systems are often performed with few replicate experiments, leading to multiple nonidentical data sets due to missing values. For example, mass spectrometry driven proteomics experiments are frequently performed with few biological or technical replicates due to sample-scarcity or due to duty-cycle or sensitivity constraints, or limited capacity of the available instrumentation, leading to incomplete results where detection of significant feature changes becomes a challenge. This problem is further exacerbated for the detection of significant changes on the peptide level, for example, in phospho-proteomics experiments. In order to assess the extent of this problem and the implications for large-scale proteome analysis, we investigated and optimized the performance of three statistical approaches by using simulated and experimental data sets with varying numbers of missing values. We applied three tools, including standard t test, moderated t test, also known as limma, and rank products for the detection of significantly changing features in simulated and experimental proteomics data sets with missing values. The rank product method was improved to work with data sets containing missing values. Extensive analysis of simulated and experimental data sets revealed that the performance of the statistical analysis tools depended on simple properties of the data sets. High-confidence results were obtained by using the limma and rank products methods for analyses of triplicate data sets that exhibited more than 1000 features and more than 50% missing values. The maximum number of differentially represented features was identified by using limma and rank products methods in a complementary manner. We therefore recommend combined usage of these methods as a novel and optimal way to detect significantly changing features in these data sets. This approach is suitable for large quantitative data sets from stable isotope labeling and mass spectrometry experiments and should be applicable to large data sets of any type. An R script that implements the improved rank products algorithm and the combined analysis is available.

Statistical design of quantitative mass spectrometry-based proteomic experiments.

PubMed

Oberg, Ann L; Vitek, Olga

2009-05-01

We review the fundamental principles of statistical experimental design, and their application to quantitative mass spectrometry-based proteomics. We focus on class comparison using Analysis of Variance (ANOVA), and discuss how randomization, replication and blocking help avoid systematic biases due to the experimental procedure, and help optimize our ability to detect true quantitative changes between groups. We also discuss the issues of pooling multiple biological specimens for a single mass analysis, and calculation of the number of replicates in a future study. When applicable, we emphasize the parallels between designing quantitative proteomic experiments and experiments with gene expression microarrays, and give examples from that area of research. We illustrate the discussion using theoretical considerations, and using real-data examples of profiling of disease.

Quantitative analysis of the text and graphic content in ophthalmic slide presentations.

PubMed

Ing, Edsel; Celo, Erdit; Ing, Royce; Weisbrod, Lawrence; Ing, Mercedes

2017-04-01

To determine the characteristics of ophthalmic digital slide presentations. Retrospective quantitative analysis. Slide presentations from a 2015 Canadian primary eye care conference were analyzed for their duration, character and word count, font size, words per minute (wpm), lines per slide, words per slide, slides per minute (spm), text density product (wpm × spm), proportion of graphic content, and Flesch Reading Ease (FRE) score using Microsoft PowerPoint and Word. The median audience evaluation score for the lectures was used to dichotomize the higher scoring lectures (HSL) from the lower scoring lectures (LSL). A priori we hypothesized that there would be a difference in the wpm, spm, text density product, and FRE score between HSL and LSL. Wilcoxon rank-sum tests with Bonferroni correction were utilized. The 17 lectures had medians of 2.5 spm, 20.3 words per slide, 5.0 lines per slide, 28-point sans serif font, 36% graphic content, and text density product of 136.4 words × slides/minute 2 . Although not statistically significant, the HSL had more wpm, fewer words per slide, more graphics per slide, greater text density, and higher FRE score than LSL. There was a statistically significant difference in the spm of the HSL (3.1 ± 1.0) versus the LSL (2.2 ± 1.0) at p = 0.0124. All presenters showed more than 1 slide per minute. The HSL showed more spm than the LSL. The descriptive statistics from this study may aid in the preparation of slides used for teaching and conferences. Copyright © 2017 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

Improving validation methods for molecular diagnostics: application of Bland-Altman, Deming and simple linear regression analyses in assay comparison and evaluation for next-generation sequencing.

PubMed

Misyura, Maksym; Sukhai, Mahadeo A; Kulasignam, Vathany; Zhang, Tong; Kamel-Reid, Suzanne; Stockley, Tracy L

2018-02-01

A standard approach in test evaluation is to compare results of the assay in validation to results from previously validated methods. For quantitative molecular diagnostic assays, comparison of test values is often performed using simple linear regression and the coefficient of determination (R 2 ), using R 2 as the primary metric of assay agreement. However, the use of R 2 alone does not adequately quantify constant or proportional errors required for optimal test evaluation. More extensive statistical approaches, such as Bland-Altman and expanded interpretation of linear regression methods, can be used to more thoroughly compare data from quantitative molecular assays. We present the application of Bland-Altman and linear regression statistical methods to evaluate quantitative outputs from next-generation sequencing assays (NGS). NGS-derived data sets from assay validation experiments were used to demonstrate the utility of the statistical methods. Both Bland-Altman and linear regression were able to detect the presence and magnitude of constant and proportional error in quantitative values of NGS data. Deming linear regression was used in the context of assay comparison studies, while simple linear regression was used to analyse serial dilution data. Bland-Altman statistical approach was also adapted to quantify assay accuracy, including constant and proportional errors, and precision where theoretical and empirical values were known. The complementary application of the statistical methods described in this manuscript enables more extensive evaluation of performance characteristics of quantitative molecular assays, prior to implementation in the clinical molecular laboratory. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Outcome of temporal lobe epilepsy surgery predicted by statistical parametric PET imaging.

PubMed

Wong, C Y; Geller, E B; Chen, E Q; MacIntyre, W J; Morris, H H; Raja, S; Saha, G B; Lüders, H O; Cook, S A; Go, R T

1996-07-01

PET is useful in the presurgical evaluation of temporal lobe epilepsy. The purpose of this retrospective study is to assess the clinical use of statistical parametric imaging in predicting surgical outcome. Interictal 18FDG-PET scans in 17 patients with surgically-treated temporal lobe epilepsy (Group A-13 seizure-free, group B = 4 not seizure-free at 6 mo) were transformed into statistical parametric imaging, with each pixel representing a z-score value by using the mean and s.d. of count distribution in each individual patient, for both visual and quantitative analysis. Mean z-scores were significantly more negative in anterolateral (AL) and mesial (M) regions on the operated side than the nonoperated side in group A (AL: p < 0.00005, M: p = 0.0097), but not in group B (AL: p = 0.46, M: p = 0.08). Statistical parametric imaging correctly lateralized 16 out of 17 patients. Only the AL region, however, was significant in predicting surgical outcome (F = 29.03, p < 0.00005). Using a cut-off z-score value of -1.5, statistical parametric imaging correctly classified 92% of temporal lobes from group A and 88% of those from Group B. The preliminary results indicate that statistical parametric imaging provides both clinically useful information for lateralization in temporal lobe epilepsy and a reliable predictive indicator of clinical outcome following surgical treatment.

40 CFR 796.2750 - Sediment and soil adsorption isotherm.

Code of Federal Regulations, 2014 CFR

2014-07-01

... are highly reproducible. The test provides excellent quantitative data readily amenable to statistical... combination of methods suitable for the identification and quantitative detection of the parent test chemical... quantitative analysis of the parent chemical. (3) Amount of parent test chemical applied, the amount recovered...

40 CFR 796.2750 - Sediment and soil adsorption isotherm.

Code of Federal Regulations, 2013 CFR

2013-07-01

... highly reproducible. The test provides excellent quantitative data readily amenable to statistical... combination of methods suitable for the identification and quantitative detection of the parent test chemical... quantitative analysis of the parent chemical. (3) Amount of parent test chemical applied, the amount recovered...

40 CFR 796.2750 - Sediment and soil adsorption isotherm.

Code of Federal Regulations, 2012 CFR

2012-07-01

... highly reproducible. The test provides excellent quantitative data readily amenable to statistical... combination of methods suitable for the identification and quantitative detection of the parent test chemical... quantitative analysis of the parent chemical. (3) Amount of parent test chemical applied, the amount recovered...

Evaluating and Reporting Statistical Power in Counseling Research

ERIC Educational Resources Information Center

Balkin, Richard S.; Sheperis, Carl J.

2011-01-01

Despite recommendations from the "Publication Manual of the American Psychological Association" (6th ed.) to include information on statistical power when publishing quantitative results, authors seldom include analysis or discussion of statistical power. The rationale for discussing statistical power is addressed, approaches to using "G*Power" to…

Quantitative assessment of Naegleria fowleri and fecal indicator bacteria in brackish water of Lake Pontchartrain, Louisiana

NASA Astrophysics Data System (ADS)

Xue, J.; Sherchan, S. P.; Lamar, F. G.; Lin, S.; Lamori, J. G.

2017-12-01

Brackish water samples from Lake Pontchartrain in Louisiana were assessed for the presence of pathogenic amoeba Naegleria fowleri, which causes primary amoebic meningoencephalitis (PAM). In our study, quantitative polymerase chain reaction (qPCR) methods were used to determine N. fowleri, E. coli, and Enterococcus in water collected from Lake Pontchartrain. A total of 158 water samples were analyzed over the 10- month sampling period. Statistically significant positive correlation between water temperature and N. fowleri concentration was observed. N. fowleri target sequence was detected at 35.4% (56/158) of the water samples from ten sites around the Lake ranged from 11.6 GC/100 ml water to 457.8 GC/100 ml water. A single factor (ANOVA) analysis shows the average concentration of N. fowleri in summer (119.8 GC/100 ml) was significantly higher than in winter (58.6 GC/100 ml) (p < 0.01). Statistically significant positive correlations were found between N. fowleri and qPCR E. coli results and N. fowleri and colilert E. coli (culture method), respectively. A weak positive correlation between E. coli and Enterococcus was observed from both qPCR (r = 0.27, p < 0.05) and culture based method (r = 0.52, p < 0.05). Meanwhile, significant positive correlation between qPCR and culture based methods for E. coli (r = 0.30, p < 0.05) and Enterococcus concentration was observed (r = 0.26, p < 0.05), respectively. Future research is needed to determine whether sediment is a source of N. fowleri found in the water column.

Effect of biofilm formation, and biocorrosion on denture base fractures.

PubMed

Sahin, Cem; Ergin, Alper; Ayyildiz, Simel; Cosgun, Erdal; Uzun, Gulay

2013-05-01

The aim of this study was to investigate the destructive effects of biofilm formation and/or biocorrosive activity of 6 different oral microorganisms. Three different heat polymerized acrylic resins (Ivocap Plus, Lucitone 550, QC 20) were used to prepare three different types of samples. Type "A" samples with "V" type notch was used to measure the fracture strength, "B" type to evaluate the surfaces with scanning electron microscopy and "C" type for quantitative biofilm assay. Development and calculation of biofilm covered surfaces on denture base materials were accomplished by SEM and quantitative biofilm assay. According to normality assumptions ANOVA or Kruskal-Wallis was selected for statistical analysis (α=0.05). Significant differences were obtained among the adhesion potential of 6 different microorganisms and there were significant differences among their adhesion onto 3 different denture base materials. Compared to the control groups after contamination with the microorganisms, the three point bending test values of denture base materials decreased significantly (P<.05); microorganisms diffused at least 52% of the denture base surface. The highest median quantitative biofilm value within all the denture base materials was obtained with P. aeruginosa on Lucitone 550. The type of denture base material did not alter the diffusion potential of the microorganisms significantly (P>.05). All the tested microorganisms had destructive effect over the structure and composition of the denture base materials.

Effect of biofilm formation, and biocorrosion on denture base fractures

PubMed Central

Ergin, Alper; Ayyildiz, Simel; Cosgun, Erdal; Uzun, Gulay

2013-01-01

PURPOSE The aim of this study was to investigate the destructive effects of biofilm formation and/or biocorrosive activity of 6 different oral microorganisms. MATERIALS AND METHODS Three different heat polymerized acrylic resins (Ivocap Plus, Lucitone 550, QC 20) were used to prepare three different types of samples. Type "A" samples with "V" type notch was used to measure the fracture strength, "B" type to evaluate the surfaces with scanning electron microscopy and "C" type for quantitative biofilm assay. Development and calculation of biofilm covered surfaces on denture base materials were accomplished by SEM and quantitative biofilm assay. According to normality assumptions ANOVA or Kruskal-Wallis was selected for statistical analysis (α=0.05). RESULTS Significant differences were obtained among the adhesion potential of 6 different microorganisms and there were significant differences among their adhesion onto 3 different denture base materials. Compared to the control groups after contamination with the microorganisms, the three point bending test values of denture base materials decreased significantly (P<.05); microorganisms diffused at least 52% of the denture base surface. The highest median quantitative biofilm value within all the denture base materials was obtained with P. aeruginosa on Lucitone 550. The type of denture base material did not alter the diffusion potential of the microorganisms significantly (P>.05). CONCLUSION All the tested microorganisms had destructive effect over the structure and composition of the denture base materials. PMID:23755339

Quantitative in vivo detection of brain cell death after hypoxia ischemia using the lipid peak at 1.3 ppm of proton magnetic resonance spectroscopy in neonatal rats.

PubMed

Ahn, So Yoon; Yoo, Hye Soo; Lee, Jang Hoon; Sung, Dong Kyung; Jung, Yu Jin; Sung, Se In; Lim, Keun Ho; Chang, Yun Sil; Lee, Jung Hee; Kim, Ki Soo; Park, Won Soon

2013-07-01

This study was performed to determine the accuracy of proton magnetic spectroscopy ((1)H-MRS) lipid peak as a noninvasive tool for quantitative in vivo detection of brain cell death. Seven day-old Sprague Dawley rats were subjected to 8% oxygen following a unilateral carotid artery ligation. For treatment, cycloheximide was given immediately after hypoxic ischemia (HI). Lipid peak was measured using (1)H-MRS at 24 hr after HI, and then brains were harvested for fluorocytometric analyses with annexin V/propidium iodide (PI) and fluorescent probe JC-1, and for adenosine-5'-triphosphate (ATP) and lactate. Increased lipid peak at 1.3 ppm measured with (1)H-MRS, apoptotic and necrotic cells, and loss of mitochondrial membrane potential (ΔΨ) at 24 hr after HI were significantly improved with cycloheximide treatment. Significantly reduced brain ATP and increased lactate levels observed at 24 hr after HI showed a tendency to improve without statistical significance with cycloheximide treatment. Lipid peak at 1.3 ppm showed significant positive correlation with both apoptotic and necrotic cells and loss of ΔΨ, and negative correlation with normal live cells. Lipid peak at 1.3 ppm measured by (1)H-MRS might be a sensitive and reliable diagnostic tool for quantitative in vivo detection of brain cell death after HI.

Quantitatively measured tremor in hand-arm vibration-exposed workers.

PubMed

Edlund, Maria; Burström, Lage; Hagberg, Mats; Lundström, Ronnie; Nilsson, Tohr; Sandén, Helena; Wastensson, Gunilla

2015-04-01

The aim of the present study was to investigate the possible increase in hand tremor in relation to hand-arm vibration (HAV) exposure in a cohort of exposed and unexposed workers. Participants were 178 male workers with or without exposure to HAV. The study is cross-sectional regarding the outcome of tremor and has a longitudinal design with respect to exposure. The dose of HAV exposure was collected via questionnaires and measurements at several follow-ups. The CATSYS Tremor Pen(®) was used for measuring postural tremor. Multiple linear regression methods were used to analyze associations between different tremor variables and HAV exposure, along with predictor variables with biological relevance. There were no statistically significant associations between the different tremor variables and cumulative HAV or current exposure. Age was a statistically significant predictor of variation in tremor outcomes for three of the four tremor variables, whereas nicotine use was a statistically significant predictor of either left or right hand or both hands for all four tremor variables. In the present study, there was no evidence of an exposure-response association between HAV exposure and measured postural tremor. Increase in age and nicotine use appeared to be the strongest predictors of tremor.

Computerized EEG analysis for studying the effect of drugs on the central nervous system.

PubMed

Rosadini, G; Cavazza, B; Rodriguez, G; Sannita, W G; Siccardi, A

1977-11-01

Samples of our experience in quantitative pharmaco-EEG are reviewed to discuss and define its applicability and limits. Simple processing systems, such as the computation of Hjorth's descriptors, are useful for on-line monitoring of drug-induced EEG modifications which are evident also at the visual visual analysis. Power spectral analysis is suitable to identify and quantify EEG effects not evident at the visual inspection. It demonstrated how the EEG effects of compounds in a long-acting formulation vary according to the sampling time and the explored cerebral area. EEG modifications not detected by power spectral analysis can be defined by comparing statistically (F test) the spectral values of the EEG from a single lead at the different samples (longitudinal comparison), or the spectral values from different leads at any sample (intrahemispheric comparison). The presently available procedures of quantitative pharmaco-EEG are effective when applied to the study of mutltilead EEG recordings in a statistically significant sample of population. They do not seem reliable in the monitoring of directing of neuropyschiatric therapies in single patients, due to individual variability of drug effects.

Derivation and evaluation of a labeled hedonic scale.

PubMed

Lim, Juyun; Wood, Alison; Green, Barry G

2009-11-01

The objective of this study was to develop a semantically labeled hedonic scale (LHS) that would yield ratio-level data on the magnitude of liking/disliking of sensation equivalent to that produced by magnitude estimation (ME). The LHS was constructed by having 49 subjects who were trained in ME rate the semantic magnitudes of 10 common hedonic descriptors within a broad context of imagined hedonic experiences that included tastes and flavors. The resulting bipolar scale is statistically symmetrical around neutral and has a unique semantic structure. The LHS was evaluated quantitatively by comparing it with ME and the 9-point hedonic scale. The LHS yielded nearly identical ratings to those obtained using ME, which implies that its semantic labels are valid and that it produces ratio-level data equivalent to ME. Analyses of variance conducted on the hedonic ratings from the LHS and the 9-point scale gave similar results, but the LHS showed much greater resistance to ceiling effects and yielded normally distributed data, whereas the 9-point scale did not. These results indicate that the LHS has significant semantic, quantitative, and statistical advantages over the 9-point hedonic scale.

[Quality evaluation of rhubarb dispensing granules based on multi-component simultaneous quantitative analysis and bioassay].

PubMed

Tan, Peng; Zhang, Hai-Zhu; Zhang, Ding-Kun; Wu, Shan-Na; Niu, Ming; Wang, Jia-Bo; Xiao, Xiao-He

2017-07-01

This study attempts to evaluate the quality of Chinese formula granules by combined use of multi-component simultaneous quantitative analysis and bioassay. The rhubarb dispensing granules were used as the model drug for demonstrative study. The ultra-high performance liquid chromatography (UPLC) method was adopted for simultaneously quantitative determination of the 10 anthraquinone derivatives (such as aloe emodin-8-O-β-D-glucoside) in rhubarb dispensing granules; purgative biopotency of different batches of rhubarb dispensing granules was determined based on compound diphenoxylate tablets-induced mouse constipation model; blood activating biopotency of different batches of rhubarb dispensing granules was determined based on in vitro rat antiplatelet aggregation model; SPSS 22.0 statistical software was used for correlation analysis between 10 anthraquinone derivatives and purgative biopotency, blood activating biopotency. The results of multi-components simultaneous quantitative analysisshowed that there was a great difference in chemical characterizationand certain differences inpurgative biopotency and blood activating biopotency among 10 batches of rhubarb dispensing granules. The correlation analysis showed that the intensity of purgative biopotency was significantly correlated with the content of conjugated anthraquinone glycosides (P<0.01), and the intensity of blood activating biopotency was significantly correlated with the content of free anthraquinone (P<0.01). In summary, the combined use of multi-component simultaneous quantitative analysis and bioassay can achieve objective quantification and more comprehensive reflection on overall quality difference among different batches of rhubarb dispensing granules. Copyright© by the Chinese Pharmaceutical Association.

Quantitative multi-modality imaging analysis of a bioabsorbable poly-L-lactic acid stent design in the acute phase: a comparison between 2- and 3D-QCA, QCU and QMSCT-CA.

PubMed

Bruining, Nico; Tanimoto, Shuzou; Otsuka, Masato; Weustink, Annick; Ligthart, Jurgen; de Winter, Sebastiaan; van Mieghem, Carlos; Nieman, Koen; de Feyter, Pim J; van Domburg, Ron T; Serruys, Patrick W

2008-08-01

To investigate if three-dimensional (3D) based quantitative techniques are comparable to each other and to explore possible differences with respect to the reference method of 2D-QCA in the acute phase and to study whether non-invasive MSCT could potentially be applied to quantify luminal dimensions of a stented coronary segment with a novel bioabsorable drug-eluting stent made of poly-l-lactic-acid (PLLA). Quantitative imaging data derived from 16 patients enrolled at our institution in a first-in-man trial (ABSORB) receiving a biodegradable stent and who were imaged with standard coronary angiography and intravascular ultrasound were compared. Shortly, after stenting the patients also underwent a MSCT procedure. Standard 2D-QCA showed significant smaller stent lengths (p < 0.01). Although, the absolute measured stent diameters and areas by 2D-QCA tend to be smaller, the differences failed to be statistically different when compared to the 3D based quantitative modalities. Measurements made by non-invasive QMSCT-CA of implanted PLLA stents appeared to be comparable to the other 3D modalities without significant differences. Three-dimensional based quantitative analyses showed similar results quantifying luminal dimensions as compared to 2D-QCA during an evaluation of a new bioabsorbable coronary stent design in the acute phase. Furthermore, in biodegradable stents made of PLLA, non-invasive QMSCT-CA can be used to quantify luminal dimensions.

Quantitative and Qualitative Study of Intestinal Flora in Neonates

PubMed Central

Sharma, Nidhi; Chaudhry, Rama; Panigrahi, Pinaki

2012-01-01

Background: In the neonatal period the developing intestinal barrier function provides a sub-optimal mucosal defense against infection. Establishment of the normal commensal micro-flora plays a vital role in this process. Aims: To determine aerobic and anaerobic bacteria by quantitative and qualitative methods from faecal samples of neonates. Settings and Design: A prospective study was carried out in two groups in a tertiary care hospital, Group A-comprised preterm infant and in group B-full term infants. Materials and Methods: Sixty two preterm infants with the weight < 1500 gm and gestation age < 34 weeks and twenty nine full term infants with 4 weeks of age were included. Quantitation of bacterial load was done by ten-fold serial dilutions on respective media. Statistical Analysis: The data were analyzed by using EPIINFO-Ver 6.04. Results and Conclusions: The predominant aerobic bacterium was Klebsiella pneumoniae. In pre term infants aerobic bacteria were colonized with an average of 2.1 and anaerobic bacteria 0.1. Quantitation showed faecal bacterial colony count ranging from 104-1013 CFU/gms. Gram negative and gram positive bacteria increased gradually over an interval of 2 to 3 weeks. Mean log CFU of gram negative bacteria and gram positive bacteria were statistically insignificant from day 3 to day 14 (P > 0.05). On day 21 there was a significant change in colonization of both bacterial sp (P < 0.05). Potential pathogenic aerobic bacteria dominate the intestinal flora of premature babies nursed in neonatal unit. There is a need to investigate interventions to offset this imbalance in gut micro-ecology of premature babies. PMID:23326075

76 FR 43353 - Agency Information Collection Activities: Proposed Collection; Comment Request; Generic Clearance...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-20

... and opinions, but are not statistical surveys that yield quantitative results that can be generalized... generic clearance for qualitative information will not be used for quantitative information collections... for submission for other generic mechanisms that are designed to yield quantitative results. The...

76 FR 13018 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-09

... statistical surveys that yield quantitative results that can be generalized to the population of study. This... information will not be used for quantitative information collections that are designed to yield reliably... generic mechanisms that are designed to yield quantitative results. Total Burden Estimate for the...

77 FR 74191 - Information Collection; Proposed Collection; Comment Request; General Services Administration...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-13

... insights on perceptions and opinions, but are not statistical surveys that yield quantitative results that.... This type of generic clearance for qualitative information will not be used for quantitative... for submission for other generic mechanisms that are designed to yield quantitative results. The...

Teaching Statistics to Social Science Students: Making It Valuable

ERIC Educational Resources Information Center

North, D.; Zewotir, T.

2006-01-01

In this age of rapid information expansion and technology, statistics is playing an ever increasing role in education, particularly also in the training of social scientists. Statistics enables the social scientist to obtain a quantitative awareness of socio-economic phenomena hence is essential in their training. Statistics, however, is becoming…

Co-administration of furosemide with albumin for overcoming diuretic resistance in patients with hypoalbuminemia: a meta-analysis.

PubMed

Kitsios, Georgios D; Mascari, Paolo; Ettunsi, Riad; Gray, Anthony W

2014-04-01

To systematically review clinical studies of co-administration of albumin and loop diuretics in hypoalbuminemic patients as a strategy to overcome diuretic resistance. Systematic search of electronic databases up to October 2012. We included randomized clinical trials of adults with hypoalbuminemia, comparing co-administration of loop diuretics and albumin versus loop diuretics alone. Quantitative data were synthesized with meta-analytic techniques for clinical, surrogate (urinary volume and urinary sodium excretion) and intermediate (pharmacokinetic and hemodynamic parameters) outcomes. Ten studies were included, of which 8 trials with crossover design were synthesized with meta-analysis. A statistically significant increase in the amount of urine volume (increment of 231 mL [95% confidence interval 135.5-326.5]) and sodium excreted (15.9 mEq [4.9-26.8]) at 8 hours were found in favor of co-administration of albumin and furosemide. These differences were no longer statistically significant at 24 hours. Meta-analyses for intermediate outcomes (ie, furosemide excretion, distribution volume etc.) did not reveal statistically significant differences. Synthesis of a heterogeneous body of evidence shows transient effects of modest clinical significance for co-administration of albumin with furosemide in hypoalbuminemic patients. Pragmatic, large-scale randomized studies are needed to delineate the role of this strategy. Copyright © 2014 Elsevier Inc. All rights reserved.

Hemorheological changes and hematometric erythrocyte characteristics in rats after sodium nitrite intoxication

NASA Astrophysics Data System (ADS)

Ivanov, Ivan; Gluhcheva, Yordanka; Petrova, Emilia; Antonova, Nadia

2014-05-01

Sodium nitrite (NaNO2) is a precursor to a variety of organic compounds (pharmaceuticals, dyes and pesticides), but it is best known as a food additive. The aim of the study is to investigate the influence of acute (i.p.) treatment of Wistar rats with NaNO2 (at the dose of 50 mg/kg b.w.) on the blood rheological properties and erythrocyte hematometric indices (Hb, HCT, RBC, MCV, RDW, MCH, MCHC). The significant differences were not found in the whole blood viscosity (WBV) values of the control and NaNO2-treated groups. The changes in the erythrocyte hematometric indices were statistically significant for RDW, MCHC and MCH at the 1st hour, five- and ten days after NaNO2 administration. Interestingly, at the day 5th of the NaNO2 treatment we obtained statistically significant lower values for the RBC count, Hb, HCT, RDW, as well as elevated indices MCV (no statistically significant), MCH, MCHC. The results obtained indicate that hemorheological and hematometric parameters examined should be monitored in cases of acute exposure to nitrites — for the purposes of clinical toxicology. The quantitative values of hematometric indices reported in our experimental model could be suitable for predicting NaNO2 intoxication and methemoglobinemia in animals and humans.

Quantitative Skills as a Graduate Learning Outcome of University Science Degree Programmes: Student Performance Explored through the "Planned-Enacted-Experienced" Curriculum Model

ERIC Educational Resources Information Center

Matthews, Kelly E.; Adams, Peter; Goos, Merrilyn

2016-01-01

Application of mathematical and statistical thinking and reasoning, typically referred to as quantitative skills, is essential for university bioscience students. First, this study developed an assessment task intended to gauge graduating students' quantitative skills. The Quantitative Skills Assessment of Science Students (QSASS) was the result,…

[Quantitative evaluation of visual gnosis in children with focal brain lesions].

PubMed

Pencheva, S; Zaprianova, L

1983-01-01

Bearing in mind the opinion of many authors on a great plasticity and interchangeability of the brain cortical functional systems in children the authors have carried out an experiment with 40 children with focal damages of the brain hemispheres, in 20 of whom the right, and in the other 20 the left hemisphere was affected. Use was made of the method of visual gnosis quantitative assessment in the modification of Pencheva and Mavlov (1975). In the children with the focal damages, more or less marked disturbances of the visual gnosis were revealed, however, no statistically significant relationship between the disturbances and the brain side were disclosed. The agnostic disorders were equally frequent in the children of both groups.

Quantitative dermatoglyphic asymmetry: a comparative study between schizophrenic patients and control groups of West Bengal, India.

PubMed

Karmakar, B; Sengupta, M

2012-01-01

Quantitative Fluctuating (FA) and Directional asymmetry (DA) of dermatoglyphics on digito-palmar complex were analyzed in a group of 111 patients (males: 61, females: 50) with schizophrenia (SZ), and compared to an ethnically matched phenotypically healthy control (males: 60, females: 60) through MANOVA, ANOVA and canonical Discriminant analyses. With few exceptions, asymmetries are higher among patients, and this is more prominent in FA than DA. Statistically significant differences were observed between patient and control groups, especially in males. In both sexes, FA of combined dermatoglyphic traits (e.g. total finger ridge count, total palmar pattern ridge count) are found to be a strong discriminator between the two groups with a correct classification of over 83% probability.

Customized Molecular Phenotyping by Quantitative Gene Expression and Pattern Recognition Analysis

PubMed Central

Akilesh, Shreeram; Shaffer, Daniel J.; Roopenian, Derry

2003-01-01

Description of the molecular phenotypes of pathobiological processes in vivo is a pressing need in genomic biology. We have implemented a high-throughput real-time PCR strategy to establish quantitative expression profiles of a customized set of target genes. It enables rapid, reproducible data acquisition from limited quantities of RNA, permitting serial sampling of mouse blood during disease progression. We developed an easy to use statistical algorithm—Global Pattern Recognition—to readily identify genes whose expression has changed significantly from healthy baseline profiles. This approach provides unique molecular signatures for rheumatoid arthritis, systemic lupus erythematosus, and graft versus host disease, and can also be applied to defining the molecular phenotype of a variety of other normal and pathological processes. PMID:12840047

Investigation on Quantitative Structure Activity Relationships of a Series of Inducible Nitric Oxide.

PubMed

Sharma, Mukesh C; Sharma, S

2016-12-01

A series of 2-dihydro-4-quinazolin with potent highly selective inhibitors of inducible nitric oxide synthase activities was subjected to quantitative structure activity relationships (QSAR) analysis. Statistically significant equations with high correlation coefficient (r 2  = 0.8219) were developed. The k-nearest neighbor model has showed good cross-validated correlation coefficient and external validation values of 0.7866 and 0.7133, respectively. The selected electrostatic field descriptors the presence of blue ball around R1 and R4 in the quinazolinamine moiety showed electronegative groups favorable for nitric oxide synthase activity. The QSAR models may lead to the structural requirements of inducible nitric oxide compounds and help in the design of new compounds.

Large-scale quantitative analysis of painting arts.

PubMed

Kim, Daniel; Son, Seung-Woo; Jeong, Hawoong

2014-12-11

Scientists have made efforts to understand the beauty of painting art in their own languages. As digital image acquisition of painting arts has made rapid progress, researchers have come to a point where it is possible to perform statistical analysis of a large-scale database of artistic paints to make a bridge between art and science. Using digital image processing techniques, we investigate three quantitative measures of images - the usage of individual colors, the variety of colors, and the roughness of the brightness. We found a difference in color usage between classical paintings and photographs, and a significantly low color variety of the medieval period. Interestingly, moreover, the increment of roughness exponent as painting techniques such as chiaroscuro and sfumato have advanced is consistent with historical circumstances.

Statistical issues in the comparison of quantitative imaging biomarker algorithms using pulmonary nodule volume as an example.

PubMed

Obuchowski, Nancy A; Barnhart, Huiman X; Buckler, Andrew J; Pennello, Gene; Wang, Xiao-Feng; Kalpathy-Cramer, Jayashree; Kim, Hyun J Grace; Reeves, Anthony P

2015-02-01

Quantitative imaging biomarkers are being used increasingly in medicine to diagnose and monitor patients' disease. The computer algorithms that measure quantitative imaging biomarkers have different technical performance characteristics. In this paper we illustrate the appropriate statistical methods for assessing and comparing the bias, precision, and agreement of computer algorithms. We use data from three studies of pulmonary nodules. The first study is a small phantom study used to illustrate metrics for assessing repeatability. The second study is a large phantom study allowing assessment of four algorithms' bias and reproducibility for measuring tumor volume and the change in tumor volume. The third study is a small clinical study of patients whose tumors were measured on two occasions. This study allows a direct assessment of six algorithms' performance for measuring tumor change. With these three examples we compare and contrast study designs and performance metrics, and we illustrate the advantages and limitations of various common statistical methods for quantitative imaging biomarker studies. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Improving Middle School Students’ Quantitative Literacy through Inquiry Lab and Group Investigation

NASA Astrophysics Data System (ADS)

Aisya, N. S. M.; Supriatno, B.; Saefudin; Anggraeni, S.

2017-02-01

The purpose of this study was to analyze the application of metacognitive strategies learning based Vee Diagram through Inquiry Lab and Group Investigation toward students’ quantitative literacy. This study compared two treatments on learning activity in middle school. The metacognitive strategies have applied to the content of environmental pollution at 7th grade. This study used a quantitative approach with quasi-experimental method. The research sample were the 7th grade students, involves 27 students in the experimental through Inquiry Lab and 27 students in the experimental through Group Investigation. The instruments that used in this research were pretest and posttest quantitative literacy skills, learning step observation sheets, and the questionnaire of teachers and students responses. As the result, N-gain average of pretest and posttest increased in both experimental groups. The average of posttest score was 61,11 for the Inquiry Lab and 54,01 to the Group Investigation. The average score of N-gain quantitative literacy skill of Inquiry Lab class was 0,492 and Group Investigation class was 0,426. Both classes of experiments showed an average N-gain in the medium category. The data has been analyzed statistically by using SPSS ver.23 and the results showed that although both the learning model can develop quantitative literacy, but there is not significantly different of improving students’ quantitative literacy between Inquiry Lab and Group Investigation in environmental pollution material.

On sweat analysis for quantitative estimation of dehydration during physical exercise.

PubMed

Ring, Matthias; Lohmueller, Clemens; Rauh, Manfred; Eskofier, Bjoern M

2015-08-01

Quantitative estimation of water loss during physical exercise is of importance because dehydration can impair both muscular strength and aerobic endurance. A physiological indicator for deficit of total body water (TBW) might be the concentration of electrolytes in sweat. It has been shown that concentrations differ after physical exercise depending on whether water loss was replaced by fluid intake or not. However, to the best of our knowledge, this fact has not been examined for its potential to quantitatively estimate TBW loss. Therefore, we conducted a study in which sweat samples were collected continuously during two hours of physical exercise without fluid intake. A statistical analysis of these sweat samples revealed significant correlations between chloride concentration in sweat and TBW loss (r = 0.41, p <; 0.01), and between sweat osmolality and TBW loss (r = 0.43, p <; 0.01). A quantitative estimation of TBW loss resulted in a mean absolute error of 0.49 l per estimation. Although the precision has to be improved for practical applications, the present results suggest that TBW loss estimation could be realizable using sweat samples.

Evaluation of a web based informatics system with data mining tools for predicting outcomes with quantitative imaging features in stroke rehabilitation clinical trials

NASA Astrophysics Data System (ADS)

Wang, Ximing; Kim, Bokkyu; Park, Ji Hoon; Wang, Erik; Forsyth, Sydney; Lim, Cody; Ravi, Ragini; Karibyan, Sarkis; Sanchez, Alexander; Liu, Brent

2017-03-01

Quantitative imaging biomarkers are used widely in clinical trials for tracking and evaluation of medical interventions. Previously, we have presented a web based informatics system utilizing quantitative imaging features for predicting outcomes in stroke rehabilitation clinical trials. The system integrates imaging features extraction tools and a web-based statistical analysis tool. The tools include a generalized linear mixed model(GLMM) that can investigate potential significance and correlation based on features extracted from clinical data and quantitative biomarkers. The imaging features extraction tools allow the user to collect imaging features and the GLMM module allows the user to select clinical data and imaging features such as stroke lesion characteristics from the database as regressors and regressands. This paper discusses the application scenario and evaluation results of the system in a stroke rehabilitation clinical trial. The system was utilized to manage clinical data and extract imaging biomarkers including stroke lesion volume, location and ventricle/brain ratio. The GLMM module was validated and the efficiency of data analysis was also evaluated.

A Quantitative Structure-Property Relationship (QSPR) Study of Aliphatic Alcohols by the Method of Dividing the Molecular Structure into Substructure

PubMed Central

Liu, Fengping; Cao, Chenzhong; Cheng, Bin

2011-01-01

A quantitative structure–property relationship (QSPR) analysis of aliphatic alcohols is presented. Four physicochemical properties were studied: boiling point (BP), n-octanol–water partition coefficient (lg POW), water solubility (lg W) and the chromatographic retention indices (RI) on different polar stationary phases. In order to investigate the quantitative structure–property relationship of aliphatic alcohols, the molecular structure ROH is divided into two parts, R and OH to generate structural parameter. It was proposed that the property is affected by three main factors for aliphatic alcohols, alkyl group R, substituted group OH, and interaction between R and OH. On the basis of the polarizability effect index (PEI), previously developed by Cao, the novel molecular polarizability effect index (MPEI) combined with odd-even index (OEI), the sum eigenvalues of bond-connecting matrix (SX1CH) previously developed in our team, were used to predict the property of aliphatic alcohols. The sets of molecular descriptors were derived directly from the structure of the compounds based on graph theory. QSPR models were generated using only calculated descriptors and multiple linear regression techniques. These QSPR models showed high values of multiple correlation coefficient (R > 0.99) and Fisher-ratio statistics. The leave-one-out cross-validation demonstrated the final models to be statistically significant and reliable. PMID:21731451

Quantitative analysis of tympanic membrane perforation: a simple and reliable method.

PubMed

Ibekwe, T S; Adeosun, A A; Nwaorgu, O G

2009-01-01

Accurate assessment of the features of tympanic membrane perforation, especially size, site, duration and aetiology, is important, as it enables optimum management. To describe a simple, cheap and effective method of quantitatively analysing tympanic membrane perforations. The system described comprises a video-otoscope (capable of generating still and video images of the tympanic membrane), adapted via a universal serial bus box to a computer screen, with images analysed using the Image J geometrical analysis software package. The reproducibility of results and their correlation with conventional otoscopic methods of estimation were tested statistically with the paired t-test and correlational tests, using the Statistical Package for the Social Sciences version 11 software. The following equation was generated: P/T x 100 per cent = percentage perforation, where P is the area (in pixels2) of the tympanic membrane perforation and T is the total area (in pixels2) for the entire tympanic membrane (including the perforation). Illustrations are shown. Comparison of blinded data on tympanic membrane perforation area obtained independently from assessments by two trained otologists, of comparative years of experience, using the video-otoscopy system described, showed similar findings, with strong correlations devoid of inter-observer error (p = 0.000, r = 1). Comparison with conventional otoscopic assessment also indicated significant correlation, comparing results for two trained otologists, but some inter-observer variation was present (p = 0.000, r = 0.896). Correlation between the two methods for each of the otologists was also highly significant (p = 0.000). A computer-adapted video-otoscope, with images analysed by Image J software, represents a cheap, reliable, technology-driven, clinical method of quantitative analysis of tympanic membrane perforations and injuries.

Effectiveness of groundwater governance structures and institutions in Tanzania

NASA Astrophysics Data System (ADS)

Gudaga, J. L.; Kabote, S. J.; Tarimo, A. K. P. R.; Mosha, D. B.; Kashaigili, J. J.

2018-05-01

This paper examines effectiveness of groundwater governance structures and institutions in Mbarali District, Mbeya Region. The paper adopts exploratory sequential research design to collect quantitative and qualitative data. A random sample of 90 groundwater users with 50% women was involved in the survey. Descriptive statistics, Kruskal-Wallis H test and Mann-Whitney U test were used to compare the differences in responses between groups, while qualitative data were subjected to content analysis. The results show that the Village Councils and Community Water Supply Organizations (COWSOs) were effective in governing groundwater. The results also show statistical significant difference on the overall extent of effectiveness of the Village Councils in governing groundwater between villages ( P = 0.0001), yet there was no significant difference ( P > 0.05) between male and female responses on the effectiveness of Village Councils, village water committees and COWSOs. The Mann-Whitney U test showed statistical significant difference between male and female responses on effectiveness of formal and informal institutions ( P = 0.0001), such that informal institutions were effective relative to formal institutions. The Kruskal-Wallis H test also showed statistical significant difference ( P ≤ 0.05) on the extent of effectiveness of formal institutions, norms and values between low, medium and high categories. The paper concludes that COWSOs were more effective in governing groundwater than other groundwater governance structures. Similarly, norms and values were more effective than formal institutions. The paper recommends sensitization and awareness creation on formal institutions so that they can influence water users' behaviour to govern groundwater.

Relationship between teacher preparedness and inquiry-based instructional practices to students' science achievement: Evidence from TIMSS 2007

NASA Astrophysics Data System (ADS)

Martin, Lynn A.

The purpose of this study was to examine the relationship between teachers' self-reported preparedness for teaching science content and their instructional practices to the science achievement of eighth grade science students in the United States as demonstrated by TIMSS 2007. Six hundred eighty-seven eighth grade science teachers in the United States representing 7,377 students responded to the TIMSS 2007 questionnaire about their instructional preparedness and their instructional practices. Quantitative data were reported. Through correlation analysis, the researcher found statistically significant positive relationships emerge between eighth grade science teachers' main area of study and their self-reported beliefs about their preparedness to teach that same content area. Another correlation analysis found a statistically significant negative relationship existed between teachers' self-reported use of inquiry-based instruction and preparedness to teach chemistry, physics and earth science. Another correlation analysis discovered a statistically significant positive relationship existed between physics preparedness and student science achievement. Finally, a correlation analysis found a statistically significant positive relationship existed between science teachers' self-reported implementation of inquiry-based instructional practices and student achievement. The data findings support the conclusion that teachers who have feelings of preparedness to teach science content and implement more inquiry-based instruction and less didactic instruction produce high achieving science students. As science teachers obtain the appropriate knowledge in science content and pedagogy, science teachers will feel prepared and will implement inquiry-based instruction in science classrooms.

Clinical Assessment of Tribulus terrestris Extract in the Treatment of Female Sexual Dysfunction

PubMed Central

Gama, Carlos RB; Lasmar, Ricardo; Gama, Gustavo F; Abreu, Camila S; Nunes, Carlos P; Geller, Mauro; Oliveira, Lisa; Santos, Alessandra

2014-01-01

This is a qualitative–quantitative study based on hospital records of female patients of reproductive age, presenting sexual dysfunction, and treated with 250 mg Tribulus terrestris extract (1 tablet thrice daily for 90 days). Safety monitoring included vital signs, physical examination, laboratory tests, and occurrence of adverse events. Efficacy analysis included results of the Female Sexual Function Index (FSFI), dehydroepiandrosterone (DHEA) levels together with total and free testosterone, and the patient and physician assessments. There was a statistically significant improvement in total FSFI scores (P < 0.0001) post-treatment, with improvement among 106 (88.33%) subjects. There was a statistically significant (P < 0.0001) increase in the level of DHEA, while the levels of both serum testosterone (P = 0.284) and free testosterone decreased (P < 0.0001). Most adverse events recorded were related to the gastrointestinal tract. Physical examination showed no significant changes post-treatment. Based on the results, it is concluded that the T. terrestris extract is safe and effective in the treatment of female sexual dysfunction. PMID:25574150

Clinical Assessment of Tribulus terrestris Extract in the Treatment of Female Sexual Dysfunction.

PubMed

Gama, Carlos Rb; Lasmar, Ricardo; Gama, Gustavo F; Abreu, Camila S; Nunes, Carlos P; Geller, Mauro; Oliveira, Lisa; Santos, Alessandra

2014-01-01

This is a qualitative-quantitative study based on hospital records of female patients of reproductive age, presenting sexual dysfunction, and treated with 250 mg Tribulus terrestris extract (1 tablet thrice daily for 90 days). Safety monitoring included vital signs, physical examination, laboratory tests, and occurrence of adverse events. Efficacy analysis included results of the Female Sexual Function Index (FSFI), dehydroepiandrosterone (DHEA) levels together with total and free testosterone, and the patient and physician assessments. There was a statistically significant improvement in total FSFI scores (P < 0.0001) post-treatment, with improvement among 106 (88.33%) subjects. There was a statistically significant (P < 0.0001) increase in the level of DHEA, while the levels of both serum testosterone (P = 0.284) and free testosterone decreased (P < 0.0001). Most adverse events recorded were related to the gastrointestinal tract. Physical examination showed no significant changes post-treatment. Based on the results, it is concluded that the T. terrestris extract is safe and effective in the treatment of female sexual dysfunction.

76 FR 12072 - Guidance for Agency Information Collection Activities: Proposed Collection; Comment Request...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-04

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77 FR 75498 - Request for Comments on a New Collection

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-20

... statistical surveys that yield quantitative results that can be generalized to the population of study. DATES... surveys that yield quantitative results that can be generalized to the population of study. This feedback... qualitative information will not be used for quantitative information collections that are designed to yield...

78 FR 21952 - Submission for OMB Review; Proposed Collection; Comment Request; General Services Administration...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-12

... insights on perceptions and opinions, but are not statistical surveys that yield quantitative results that.... This type of generic clearance for qualitative information will not be used for quantitative... quantitative results. The Digital Government Strategy released by the White House in May 2012 drives agencies...

Combined visual and semi-quantitative assessment of 123I-FP-CIT SPECT for the diagnosis of dopaminergic neurodegenerative diseases.

PubMed

Ueda, Jun; Yoshimura, Hajime; Shimizu, Keiji; Hino, Megumu; Kohara, Nobuo

2017-07-01

Visual and semi-quantitative assessments of 123 I-FP-CIT single-photon emission computed tomography (SPECT) are useful for the diagnosis of dopaminergic neurodegenerative diseases (dNDD), including Parkinson's disease, dementia with Lewy bodies, progressive supranuclear palsy, multiple system atrophy, and corticobasal degeneration. However, the diagnostic value of combined visual and semi-quantitative assessment in dNDD remains unclear. Among 239 consecutive patients with a newly diagnosed possible parkinsonian syndrome who underwent 123 I-FP-CIT SPECT in our medical center, 114 patients with a disease duration less than 7 years were diagnosed as dNDD with the established criteria or as non-dNDD according to clinical judgment. We retrospectively examined their clinical characteristics and visual and semi-quantitative assessments of 123 I-FP-CIT SPECT. The striatal binding ratio (SBR) was used as a semi-quantitative measure of 123 I-FP-CIT SPECT. We calculated the sensitivity and specificity of visual assessment alone, semi-quantitative assessment alone, and combined visual and semi-quantitative assessment for the diagnosis of dNDD. SBR was correlated with visual assessment. Some dNDD patients with a normal visual assessment had an abnormal SBR, and vice versa. There was no statistically significant difference between sensitivity of the diagnosis with visual assessment alone and semi-quantitative assessment alone (91.2 vs. 86.8%, respectively, p = 0.29). Combined visual and semi-quantitative assessment demonstrated superior sensitivity (96.7%) to visual assessment (p = 0.03) or semi-quantitative assessment (p = 0.003) alone with equal specificity. Visual and semi-quantitative assessments of 123 I-FP-CIT SPECT are helpful for the diagnosis of dNDD, and combined visual and semi-quantitative assessment shows superior sensitivity with equal specificity.

Doctoral Training in Statistics, Measurement, and Methodology in Psychology: Replication and Extension of Aiken, West, Sechrest, and Reno's (1990) Survey of PhD Programs in North America

ERIC Educational Resources Information Center

Aiken, Leona S.; West, Stephen G.; Millsap, Roger E.

2008-01-01

In a survey of all PhD programs in psychology in the United States and Canada, the authors documented the quantitative methodology curriculum (statistics, measurement, and research design) to examine the extent to which innovations in quantitative methodology have diffused into the training of PhDs in psychology. In all, 201 psychology PhD…

Econophysical visualization of Adam Smith’s invisible hand

NASA Astrophysics Data System (ADS)

Cohen, Morrel H.; Eliazar, Iddo I.

2013-02-01

Consider a complex system whose macrostate is statistically observable, but yet whose operating mechanism is an unknown black-box. In this paper we address the problem of inferring, from the system’s macrostate statistics, the system’s intrinsic force yielding the observed statistics. The inference is established via two diametrically opposite approaches which result in the very same intrinsic force: a top-down approach based on the notion of entropy, and a bottom-up approach based on the notion of Langevin dynamics. The general results established are applied to the problem of visualizing the intrinsic socioeconomic force-Adam Smith’s invisible hand-shaping the distribution of wealth in human societies. Our analysis yields quantitative econophysical representations of figurative socioeconomic forces, quantitative definitions of “poor” and “rich”, and a quantitative characterization of the “poor-get-poorer” and the “rich-get-richer” phenomena.

PANDA-view: An easy-to-use tool for statistical analysis and visualization of quantitative proteomics data.

PubMed

Chang, Cheng; Xu, Kaikun; Guo, Chaoping; Wang, Jinxia; Yan, Qi; Zhang, Jian; He, Fuchu; Zhu, Yunping

2018-05-22

Compared with the numerous software tools developed for identification and quantification of -omics data, there remains a lack of suitable tools for both downstream analysis and data visualization. To help researchers better understand the biological meanings in their -omics data, we present an easy-to-use tool, named PANDA-view, for both statistical analysis and visualization of quantitative proteomics data and other -omics data. PANDA-view contains various kinds of analysis methods such as normalization, missing value imputation, statistical tests, clustering and principal component analysis, as well as the most commonly-used data visualization methods including an interactive volcano plot. Additionally, it provides user-friendly interfaces for protein-peptide-spectrum representation of the quantitative proteomics data. PANDA-view is freely available at https://sourceforge.net/projects/panda-view/. 1987ccpacer@163.com and zhuyunping@gmail.com. Supplementary data are available at Bioinformatics online.

Middle school students' earthquake content and preparedness knowledge - A mixed method study

NASA Astrophysics Data System (ADS)

Henson, Harvey, Jr.

The purpose of this study was to assess the effect of earthquake instruction on students' earthquake content and preparedness for earthquakes. This study used an innovative direct instruction on earthquake science content and concepts with an inquiry-based group activity on earthquake safety followed by an earthquake simulation and preparedness video to help middle school students understand and prepare for the regional seismic threat. A convenience sample of 384 sixth and seventh grade students at two small middle schools in southern Illinois was used in this study. Qualitative information was gathered using open-ended survey questions, classroom observations, and semi-structured interviews. Quantitative data were collected using a 21 item content questionnaire administered to test students' General Earthquake Knowledge, Local Earthquake Knowledge, and Earthquake Preparedness Knowledge before and after instruction. A pre-test and post-test survey Likert scale with 21 items was used to collect students' perceptions and attitudes. Qualitative data analysis included quantification of student responses to the open-ended questions and thematic analysis of observation notes and interview transcripts. Quantitative datasets were analyzed using descriptive and inferential statistical methods, including t tests to evaluate the differences in means scores between paired groups before and after interventions and one-way analysis of variance (ANOVA) to test for differences between mean scores of the comparison groups. Significant mean differences between groups were further examined using a Dunnett's C post hoc statistical analysis. Integration and interpretation of the qualitative and quantitative results of the study revealed a significant increase in general, local and preparedness earthquake knowledge among middle school students after the interventions. The findings specifically indicated that these students felt most aware and prepared for an earthquake after an intervention that consisted of an inquiry-based group discussion on safety, earthquake content presentation and earthquake simulation video presentation on preparedness. Variations of the intervention, including no intervention, were not as effective in significantly increasing students' conceptual learning of earthquake knowledge.

Whole-body concentrations of elements in three fish species from offshore oil platforms and natural areas in the Southern California Bight, USA

USGS Publications Warehouse

Love, Milton S.; Saiki, Michael K.; May, Thomas W.; Yee, Julie L.

2013-01-01

elements. Forty-two elements were excluded from statistical comparisons as they (1) consisted of major cations that were unlikely to accumulate to potentially toxic concentrations; (2) were not detected by the analytical procedures; or (3) were detected at concentrations too low to yield reliable quantitative measurements. The remaining 21 elements consisted of aluminum, arsenic, barium, cadmium, chromium, cobalt, copper, gallium, iron, lead, lithium, manganese, mercury, nickel, rubidium, selenium, strontium, tin, titanium, vanadium, and zinc. Statistical comparisons of these elements indicated that none consistently exhibited higher concentrations at oil platforms than at natural areas. However, the concentrations of copper, selenium, titanium, and vanadium in Pacific sanddab were unusual because small individuals exhibited either no differences between oil platforms and natural areas or significantly lower concentrations at oil platforms than at natural areas, whereas large individuals exhibited significantly higher concentrations at oil platforms than at natural areas.

Publication Bias ( The "File-Drawer Problem") in Scientific Inference

NASA Technical Reports Server (NTRS)

Scargle, Jeffrey D.; DeVincenzi, Donald (Technical Monitor)

1999-01-01

Publication bias arises whenever the probability that a study is published depends on the statistical significance of its results. This bias, often called the file-drawer effect since the unpublished results are imagined to be tucked away in researchers' file cabinets, is potentially a severe impediment to combining the statistical results of studies collected from the literature. With almost any reasonable quantitative model for publication bias, only a small number of studies lost in the file-drawer will produce a significant bias. This result contradicts the well known Fail Safe File Drawer (FSFD) method for setting limits on the potential harm of publication bias, widely used in social, medical and psychic research. This method incorrectly treats the file drawer as unbiased, and almost always miss-estimates the seriousness of publication bias. A large body of not only psychic research, but medical and social science studies, has mistakenly relied on this method to validate claimed discoveries. Statistical combination can be trusted only if it is known with certainty that all studies that have been carried out are included. Such certainty is virtually impossible to achieve in literature surveys.

Agriculture, population growth, and statistical analysis of the radiocarbon record.

PubMed

Zahid, H Jabran; Robinson, Erick; Kelly, Robert L

2016-01-26

The human population has grown significantly since the onset of the Holocene about 12,000 y ago. Despite decades of research, the factors determining prehistoric population growth remain uncertain. Here, we examine measurements of the rate of growth of the prehistoric human population based on statistical analysis of the radiocarbon record. We find that, during most of the Holocene, human populations worldwide grew at a long-term annual rate of 0.04%. Statistical analysis of the radiocarbon record shows that transitioning farming societies experienced the same rate of growth as contemporaneous foraging societies. The same rate of growth measured for populations dwelling in a range of environments and practicing a variety of subsistence strategies suggests that the global climate and/or endogenous biological factors, not adaptability to local environment or subsistence practices, regulated the long-term growth of the human population during most of the Holocene. Our results demonstrate that statistical analyses of large ensembles of radiocarbon dates are robust and valuable for quantitatively investigating the demography of prehistoric human populations worldwide.

The new statistics: why and how.

PubMed

Cumming, Geoff

2014-01-01

We need to make substantial changes to how we conduct research. First, in response to heightened concern that our published research literature is incomplete and untrustworthy, we need new requirements to ensure research integrity. These include prespecification of studies whenever possible, avoidance of selection and other inappropriate data-analytic practices, complete reporting, and encouragement of replication. Second, in response to renewed recognition of the severe flaws of null-hypothesis significance testing (NHST), we need to shift from reliance on NHST to estimation and other preferred techniques. The new statistics refers to recommended practices, including estimation based on effect sizes, confidence intervals, and meta-analysis. The techniques are not new, but adopting them widely would be new for many researchers, as well as highly beneficial. This article explains why the new statistics are important and offers guidance for their use. It describes an eight-step new-statistics strategy for research with integrity, which starts with formulation of research questions in estimation terms, has no place for NHST, and is aimed at building a cumulative quantitative discipline.

[Adequate application of quantitative and qualitative statistic analytic methods in acupuncture clinical trials].

PubMed

Tan, Ming T; Liu, Jian-ping; Lao, Lixing

2012-08-01

Recently, proper use of the statistical methods in traditional Chinese medicine (TCM) randomized controlled trials (RCTs) has received increased attention. Statistical inference based on hypothesis testing is the foundation of clinical trials and evidence-based medicine. In this article, the authors described the methodological differences between literature published in Chinese and Western journals in the design and analysis of acupuncture RCTs and the application of basic statistical principles. In China, qualitative analysis method has been widely used in acupuncture and TCM clinical trials, while the between-group quantitative analysis methods on clinical symptom scores are commonly used in the West. The evidence for and against these analytical differences were discussed based on the data of RCTs assessing acupuncture for pain relief. The authors concluded that although both methods have their unique advantages, quantitative analysis should be used as the primary analysis while qualitative analysis can be a secondary criterion for analysis. The purpose of this paper is to inspire further discussion of such special issues in clinical research design and thus contribute to the increased scientific rigor of TCM research.

A five year review of paediatric burns and social deprivation: Is there a link?

PubMed

Richards, Helen; Kokocinska, Maria; Lewis, Darren

2017-09-01

To establish if there is a correlation between burn incidence and social deprivation in order to formulate a more effective burns prevention strategy. A quantitative retrospective review of International Burn Injury Database (IBID) was carried out over a period from 2006 to 2011 to obtain data for children referred to our burns centre in West Midlands. Social deprivation scores for geographical areas were obtained from Office of National Statistics (ONS). Statistical analysis was carried out using Graphpad Prism. 1688 children were reviewed at our burns centre. Statistical analysis using Pearson correlation coefficient showed a slight association between social deprivation and increasing burn incidence r 2 =0.1268, 95% confidence interval 0.018-0.219, p value<0.0001. There was a slight male preponderance (58%). The most common mechanism of injury was scalding (61%). The most commonly affected age group were 1-2 year olds (38%). There were statistically significant differences in the ethnicity of children with significantly more children from Asian and African backgrounds being referred compared to Caucasian children. We found that appropriate first aid was administered in 67% of cases overall. We did not find a statistically significant link between first aid provision and social deprivation score. There was only a slight positive correlation between social deprivation and burn incidence. However, there did not seem to be any change in mechanism of burn in the most deprived groups compared to overall pattern, nor was there a significant difference in appropriate first aid provision. It would seem that dissemination of burn prevention strategies and first aid advice need to be improved across all geographical areas as this was uniformly lacking and the increased burn incidence in more socially deprived groups, although present, was not statistically significant. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

Preferences for teaching methods in a baccalaureate nursing program: how second-degree and traditional students differ.

PubMed

Walker, Jean T; Martin, Tina M; Haynie, Lisa; Norwood, Anne; White, Jill; Grant, LaVerne

2007-01-01

Accelerated baccalaureate nursing programs are in great demand in the United States. Currently there are 197 such programs, but little research has been conducted on student characteristics and program outcomes. This quantitative study explores preferences of second-degree students and traditional generic students with regard to teaching methods and relationships with faculty. The results indicate that statistically significant differences exist between the two groups of students. Three areas of significance are ability for self-directed learning, expectations of faculty and classroom structure, and obtaining a grade that really matters.

Three-dimensional quantitative structure-activity relationship study on antioxidant capacity of curcumin analogues

NASA Astrophysics Data System (ADS)

Chen, Bohong; Zhu, Zhibo; Chen, Min; Dong, Wenqi; Li, Zhen

2014-03-01

A comparative molecular similarity indices analysis (CoMSIA) was performed on a set of 27 curcumin-like diarylpentanoid analogues with the radical scavenging activities. A significant cross-validated correlation coefficient Q2 (0.784), SEP (0.042) for CoMSIA were obtained, indicating the statistical significance of the correlation. Further we adopt a rational approach toward the selection of substituents at various positions in our scaffold,and finally find the favored and disfavoured regions for the enhanced antioxidative activity. The results have been used as a guide to design compounds that, potentially, have better activity against oxidative damage.

Survey of Native English Speakers and Spanish-Speaking English Language Learners in Tertiary Introductory Statistics

ERIC Educational Resources Information Center

Lesser, Lawrence M.; Wagler, Amy E.; Esquinca, Alberto; Valenzuela, M. Guadalupe

2013-01-01

The framework of linguistic register and case study research on Spanish-speaking English language learners (ELLs) learning statistics informed the construction of a quantitative instrument, the Communication, Language, And Statistics Survey (CLASS). CLASS aims to assess whether ELLs and non-ELLs approach the learning of statistics differently with…

The Preparedness of Preservice Secondary Mathematics Teachers to Teach Statistics: A Cross-Institutional Mixed Methods Study

ERIC Educational Resources Information Center

Lovett, Jennifer Nickell

2016-01-01

The purpose of this study is to provide researchers, mathematics educators, and statistics educators information about the current state of preservice secondary mathematics teachers' preparedness to teach statistics. To do so, this study employed an explanatory mixed methods design to quantitatively examine the statistical knowledge and statistics…

Quantitative agreement between [(15)O]H2O PET and model free QUASAR MRI-derived cerebral blood flow and arterial blood volume.

PubMed

Heijtel, D F R; Petersen, E T; Mutsaerts, H J M M; Bakker, E; Schober, P; Stevens, M F; van Berckel, B N M; Majoie, C B L M; Booij, J; van Osch, M J P; van Bavel, E T; Boellaard, R; Lammertsma, A A; Nederveen, A J

2016-04-01

The purpose of this study was to assess whether there was an agreement between quantitative cerebral blood flow (CBF) and arterial cerebral blood volume (CBVA) measurements by [(15)O]H2O positron emission tomography (PET) and model-free QUASAR MRI. Twelve healthy subjects were scanned within a week in separate MRI and PET imaging sessions, after which quantitative and qualitative agreement between both modalities was assessed for gray matter, white matter and whole brain region of interests (ROI). The correlation between CBF measurements obtained with both modalities was moderate to high (r(2): 0.28-0.60, P < 0.05), although QUASAR significantly underestimated CBF by 30% (P < 0.001). CBVA was moderately correlated (r(2): 0.28-0.43, P < 0.05), with QUASAR yielding values that were only 27% of the [(15)O]H2O-derived values (P < 0.001). Group-wise voxel statistics identified minor areas with significant contrast differences between [(15)O]H2O PET and QUASAR MRI, indicating similar qualitative CBVA and CBF information by both modalities. In conclusion, the results of this study demonstrate that QUASAR MRI and [(15)O]H2O PET provide similar CBF and CBVA information, but with systematic quantitative discrepancies. Copyright © 2016 John Wiley & Sons, Ltd.

Quantitative contrast-enhanced ultrasound evaluation of pathological complete response in patients with locally advanced breast cancer receiving neoadjuvant chemotherapy.

PubMed

Wan, Cai-Feng; Liu, Xue-Song; Wang, Lin; Zhang, Jie; Lu, Jin-Song; Li, Feng-Hua

2018-06-01

To clarify whether the quantitative parameters of contrast-enhanced ultrasound (CEUS) can be used to predict pathological complete response (pCR) in patients with locally advanced breast cancer receiving neoadjuvant chemotherapy (NAC). Fifty-one patients with histologically proved locally advanced breast cancer scheduled for NAC were enrolled. The quantitative data for CEUS and the tumor diameter were collected at baseline and before surgery, and compared with the pathological response. Multiple logistic regression analysis was performed to examine quantitative parameters at CEUS and the tumor diameter to predict the pCR, and receiver operating characteristic (ROC) curve analysis was used as a summary statistic. Multiple logistic regression analysis revealed that PEAK (the maximum intensity of the time-intensity curve during bolus transit), PEAK%, TTP% (time to peak), and diameter% were significant independent predictors of pCR, and the area under the ROC curve was 0.932(Az 1 ), and the sensitivity and specificity to predict pCR were 93.7% and 80.0%. The area under the ROC curve for the quantitative parameters was 0.927(Az 2 ), and the sensitivity and specificity to predict pCR were 81.2% and 94.3%. For diameter%, the area under the ROC curve was 0.786 (Az 3 ), and the sensitivity and specificity to predict pCR were 93.8% and 54.3%. The values of Az 1 and Az 2 were significantly higher than that of Az 3 (P = 0.027 and P = 0.034, respectively). However, there was no significant difference between the values of Az 1 and Az 2 (P = 0.825). Quantitative analysis of tumor blood perfusion with CEUS is superior to diameter% to predict pCR, and can be used as a functional technique to evaluate tumor response to NAC. Copyright © 2018. Published by Elsevier B.V.

Correlation between quantitative and semiquantitative parameters in DCE-MRI with a blood pool agent in rectal cancer: can semiquantitative parameters be used as a surrogate for quantitative parameters?

PubMed

Dijkhoff, Rebecca A P; Maas, Monique; Martens, Milou H; Papanikolaou, Nikolaos; Lambregts, Doenja M J; Beets, Geerard L; Beets-Tan, Regina G H

2017-05-01

The aim of this study was to assess correlation between quantitative and semiquantitative parameters in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in rectal cancer patients, both in a primary staging and restaging setting. Nineteen patients were included with DCE-MRI before and/or after neoadjuvant therapy. DCE-MRI was performed with gadofosveset trisodium (Ablavar ® , Lantheus Medical Imaging, North Billerica, Massachusetts, USA). Regions of interest were placed in the tumor and quantitative parameters were extracted with Olea Sphere 2.2 software permeability module using the extended Tofts model. Semiquantitative parameters were calculated on a pixel-by-pixel basis. Spearman rank correlation tests were used for assessment of correlation between parameters. A p value ≤0.05 was considered statistically significant. Strong positive correlations were found between mean peak enhancement and mean K trans : 0.79 (all patients, p<0.0001), 0.83 (primary staging, p = 0.003), and 0.81 (restaging, p = 0.054). Mean wash-in correlated significantly with mean V p and K ep (0.79 and 0.58, respectively, p<0.0001 and p = 0.009) in all patients. Mean wash-in showed a significant correlation with mean K ep (0.67, p = 0.033) in the primary staging group. On the restaging MRI, mean wash-in only strongly correlated with mean V p (0.81, p = 0.054). This study shows a strong correlation between quantitative and semiquantitative parameters in DCE-MRI for rectal cancer. Peak enhancement correlates strongly with K trans and wash-in showed strong correlation with V p and K ep . These parameters have been reported to predict tumor aggressiveness and response in rectal cancer. Therefore, semiquantitative analyses might be a surrogate for quantitative analyses.

Obscure phenomena in statistical analysis of quantitative structure-activity relationships. Part 1: Multicollinearity of physicochemical descriptors.

PubMed

Mager, P P; Rothe, H

1990-10-01

Multicollinearity of physicochemical descriptors leads to serious consequences in quantitative structure-activity relationship (QSAR) analysis, such as incorrect estimators and test statistics of regression coefficients of the ordinary least-squares (OLS) model applied usually to QSARs. Beside the diagnosis of the known simple collinearity, principal component regression analysis (PCRA) also allows the diagnosis of various types of multicollinearity. Only if the absolute values of PCRA estimators are order statistics that decrease monotonically, the effects of multicollinearity can be circumvented. Otherwise, obscure phenomena may be observed, such as good data recognition but low predictive model power of a QSAR model.

Adaptive statistical iterative reconstruction: reducing dose while preserving image quality in the pediatric head CT examination.

PubMed

McKnight, Colin D; Watcharotone, Kuanwong; Ibrahim, Mohannad; Christodoulou, Emmanuel; Baer, Aaron H; Parmar, Hemant A

2014-08-01

Over the last decade there has been escalating concern regarding the increasing radiation exposure stemming from CT exams, particularly in children. Adaptive statistical iterative reconstruction (ASIR) is a relatively new and promising tool to reduce radiation dose while preserving image quality. While encouraging results have been found in adult head and chest and body imaging, validation of this technique in pediatric population is limited. The objective of our study was to retrospectively compare the image quality and radiation dose of pediatric head CT examinations obtained with ASIR compared to pediatric head CT examinations without ASIR in a large patient population. Retrospective analysis was performed on 82 pediatric head CT examinations. This group included 33 pediatric head CT examinations obtained with ASIR and 49 pediatric head CT examinations without ASIR. Computed tomography dose index (CTDIvol) was recorded on all examinations. Quantitative analysis consisted of standardized measurement of attenuation and the standard deviation at the bilateral centrum semiovale and cerebellar white matter to evaluate objective noise. Qualitative analysis consisted of independent assessment by two radiologists in a blinded manner of gray-white differentiation, sharpness and overall diagnostic quality. The average CTDIvol value of the ASIR group was 21.8 mGy (SD = 4.0) while the average CTDIvol for the non-ASIR group was 29.7 mGy (SD = 13.8), reflecting a statistically significant reduction in CTDIvol in the ASIR group (P < 0.01). There were statistically significant reductions in CTDI for the 3- to 12-year-old ASIR group as compared to the 3- to 12-year-old non-ASIR group (21.5 mGy vs. 30.0 mGy; P = 0.004) as well as statistically significant reductions in CTDI for the >12-year-old ASIR group as compared to the >12-year-old non-ASIR group (29.7 mGy vs. 49.9 mGy; P = 0.0002). Quantitative analysis revealed no significant difference in the homogeneity of variance in the ASIR group compared to the non-ASIR group. Radiologist assessment of gray-white differentiation, sharpness and overall diagnostic quality in ASIR examinations was not substantially different compared to non-ASIR examinations. The use of ASIR in pediatric head CT examinations allows for a 28% CTDIvol reduction in the 3- to 12-year-old age group and a 48% reduction in the >12-year-old age group without substantially affecting image quality.

Apoptosis after gamma irradiation. Is it an important cell death modality?

PubMed Central

Siles, E.; Villalobos, M.; Jones, L.; Guerrero, R.; Eady, J. J.; Valenzuela, M. T.; Núñez, M. I.; McMillan, T. J.; Ruiz de Almodóvar, J. M.

1998-01-01

Apoptosis and necrosis are two different forms of cell death that can be induced by cytotoxic stress, such as ionizing radiation. We have studied the importance of apoptotic death induced after treatment with 6 Gy of gamma-irradiation in a panel of eight human tumour cell lines of different radiosensitivities. Three different techniques based on the detection of DNA fragmentation have been used, a qualitative one--DNA ladder formation --and two quantitative approaches--in situ tailing and comet assay. No statistically significant relationship between the two quantitative assays was found (r= 0.327, P = 0.159) so these methods seem to show different aspects of the process of cell death. The presence of the DNA ladder related well to the end-labelling method in that the least amount of end labelling was seen in samples in which necrotic degradation rather than apoptotic ladders were seen. However, as the results obtained by the comet assay are not in agreement with the DNA ladder experiments, we suggest that the distinction between the degraded DNA produced by apoptosis and necrosis may be difficult by this technique. Finally, although apoptosis has been proposed to be dependent on p53 functionality, and this may explain differences in cellular radiosensitivity, no statistically significant relationship was found between these parameters and apoptosis in the eight cell lines studied. PMID:9862569

Noncontact three-dimensional evaluation of surface alterations and wear in NiTi endodontic instruments.

PubMed

Ferreira, Fabiano Guerra; Barbosa, Igor Bastos; Scelza, Pantaleo; Montagnana, Marcello Bulhões; Russano, Daniel; Neff, John; Scelza, Miriam Zaccaro

2017-09-28

The aim of this study was to undertake a qualitative and quantitative assessment of nanoscale alterations and wear on the surfaces of nickel-titanium (NiTi) endodontic instruments, before and after use, through a high-resolution, noncontact, three-dimensional optical profiler, and to verify the accuracy of the evaluation method. Cutting blade surfaces of two different brands of NiTi endodontic instruments, Reciproc R25 (n = 5) and WaveOne Primary (n = 5), were examined and compared before and after two uses in simulated root canals made in clear resin blocks. The analyses were performed on three-dimensional images which were obtained from surface areas measuring 211 × 211 µm, located 3 mm from their tips. The quantitative evaluation of the samples was conducted before and after the first and second usage, by the recordings of three amplitude parameters. The data were subjected to statistical analysis at a 5% level of significance. The results revealed statistically significant increases in the surface wear of both instruments groups after the second use. The presence of irregularities was found on the surface topography of all the instruments, before and after use. Regardless of the evaluation stage, most of the defects were observed in the WaveOne instruments. The three-dimensional technique was suitable and effective for the accurate investigation of the same surfaces of the instruments in different periods of time.

Radiation dose reduction in CT with adaptive statistical iterative reconstruction (ASIR) for patients with bronchial carcinoma and intrapulmonary metastases.

PubMed

Schäfer, M-L; Lüdemann, L; Böning, G; Kahn, J; Fuchs, S; Hamm, B; Streitparth, F

2016-05-01

To compare the radiation dose and image quality of 64-row chest computed tomography (CT) in patients with bronchial carcinoma or intrapulmonary metastases using full-dose CT reconstructed with filtered back projection (FBP) at baseline and reduced dose with 40% adaptive statistical iterative reconstruction (ASIR) at follow-up. The chest CT images of patients who underwent FBP and ASIR studies were reviewed. Dose-length products (DLP), effective dose, and size-specific dose estimates (SSDEs) were obtained. Image quality was analysed quantitatively by signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) measurement. In addition, image quality was assessed by two blinded radiologists evaluating images for noise, contrast, artefacts, visibility of small structures, and diagnostic acceptability using a five-point scale. The ASIR studies showed 36% reduction in effective dose compared with the FBP studies. The qualitative and quantitative image quality was good to excellent in both protocols, without significant differences. There were also no significant differences for SNR except for the SNR of lung surrounding the tumour (FBP: 35±17, ASIR: 39±22). A protocol with 40% ASIR can provide approximately 36% dose reduction in chest CT of patients with bronchial carcinoma or intrapulmonary metastases while maintaining excellent image quality. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

The influence of previous subject experience on interactions during peer instruction in an introductory physics course: A mixed methods analysis

NASA Astrophysics Data System (ADS)

Vondruska, Judy A.

Over the past decade, peer instruction and the introduction of student response systems has provided a means of improving student engagement and achievement in large-lecture settings. While the nature of the student discourse occurring during peer instruction is less understood, existing studies have shown student ideas about the subject, extraneous cues, and confidence level appear to matter in the student-student discourse. Using a mixed methods research design, this study examined the influence of previous subject experience on peer instruction in an introductory, one-semester Survey of Physics course. Quantitative results indicated students in discussion pairs where both had previous subject experience were more likely to answer clicker question correctly both before and after peer discussion compared to student groups where neither partner had previous subject experience. Students in mixed discussion pairs were not statistically different in correct response rates from the other pairings. There was no statistically significant difference between the experience pairs on unit exam scores or the Peer Instruction Partner Survey. Although there was a statistically significant difference between the pre-MPEX and post-MPEX scores, there was no difference between the members of the various subject experience peer discussion pairs. The qualitative study, conducted after the quantitative study, helped to inform the quantitative results by exploring the nature of the peer interactions through survey questions and a series of focus groups discussions. While the majority of participants described a benefit to the use of clickers in the lecture, their experience with their discussion partners varied. Students with previous subject experience tended to describe peer instruction more positively than students who did not have previous subject experience, regardless of the experience level of their partner. They were also more likely to report favorable levels of comfort with the peer instruction experience. Students with no previous subject experience were more likely to describe a level of discomfort being assigned a stranger for a discussion partner and were more likely to report communication issues with their partner. Most group members, regardless of previous subject experience, related deeper discussions occurring when partners did not initially have the same answer to the clicker questions.

Bilateral cartilage T2 mapping 9 years after Mega-OATS implantation at the knee: a quantitative 3T MRI study.

PubMed

Jungmann, P M; Brucker, P U; Baum, T; Link, T M; Foerschner, F; Minzlaff, P; Banke, I J; Saier, T; Imhoff, A B; Rummeny, E J; Bauer, J S

2015-12-01

To evaluate morphological and quantitative MR findings 9 years after autograft transfer of the posterior femoral condyle (Mega-OATS) and to correlate these findings with clinical outcomes. Quantitative MR measurements were also obtained of the contralateral knee and the utility as reference standard was investigated. Both knees of 20 patients with Mega-OATS osteochondral repair at the medial femoral condyle (MFC) were studied using 3T MRI 9 years after the procedure. MR-sequences included morphological sequences and a 2D multislice multiecho (MSME) spin echo (SE) sequence for quantitative cartilage T2 mapping. Cartilage segmentation was performed at the cartilage repair site and six additional knee compartments. Semi-quantitative MR observation of cartilage repair tissue (MOCART) scores and clinical Lysholm scores were obtained. Paired t-tests and Spearman correlations were used for statistical analysis. Global T2-values were significantly higher at ipsilateral knees compared to contralateral knees (42.1 ± 3.0 ms vs 40.4 ± 2.6 ms, P = 0.018). T2-values of the Mega-OATS site correlated significantly with MOCART scores (R = -0.64, P = 0.006). The correlations between MOCART and Lysholm scores and between absolute T2-values and Lysholm scores were not significant (P > 0.05). However, higher T2 side-to-side differences at the femoral condyles correlated significantly with more severe clinical symptoms (medial, R = -0.53, P = 0.030; lateral, R = -0.51, P = 0.038). Despite long-term survival, 9 years after Mega-OATS procedures, T2-values of the grafts were increased compared to contralateral knees. Clinical scores correlated best with T2 side-to-side differences of the femoral condyles, indicating that intraindividual adjustment may be beneficial for outcome evaluation. Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Things we still haven't learned (so far).

PubMed

Ivarsson, Andreas; Andersen, Mark B; Stenling, Andreas; Johnson, Urban; Lindwall, Magnus

2015-08-01

Null hypothesis significance testing (NHST) is like an immortal horse that some researchers have been trying to beat to death for over 50 years but without any success. In this article we discuss the flaws in NHST, the historical background in relation to both Fisher's and Neyman and Pearson's statistical ideas, the common misunderstandings of what p < .05 actually means, and the 2010 APA publication manual's clear, but most often ignored, instructions to report effect sizes and to interpret what they all mean in the real world. In addition, we discuss how Bayesian statistics can be used to overcome some of the problems with NHST. We then analyze quantitative articles published over the past three years (2012-2014) in two top-rated sport and exercise psychology journals to determine whether we have learned what we should have learned decades ago about our use and meaningful interpretations of statistics.

Epistemological and methodological significance of quantitative studies of psychomotor activity for the explanation of clinical depression.

PubMed

Terziivanova, Petya; Haralanov, Svetlozar

2012-12-01

Psychomotor disturbances have been regarded as cardinal symptoms of depression for centuries and their objective assessment may have predictive value with respect to the severity of clinical depression, treatment outcome and prognosis of the affective disorder. Montgomery-Åsberg Depression Rating Scale (MADRS) and Hamilton Rating Scale for Anxiety (HAM-A). Psychomotor indicators of activity and reactivity were objectively recorded and measured by means of computerized ultrasonographic craniocorpography. We found a statistically significant correlation between disturbances in psychomotor indicators and MADRS total score (r = 0.4; P < 0.0001). The severity of HAM-A total score had no statistically significant correlation with psychomotor indicators (P > 0.05). We found that different items of MADRS and HAM-A correlated with psychomotor disturbances of different strength and significance. Objectively, measured psychomotor retardation was associated with greater severity of depressive symptoms assessed at the clinical level. Integration between different methods is needed in order to improve understanding of the psychopathology and the neurobiology of a disputable diagnosis such as clinical depression. © 2012 Blackwell Publishing Ltd.

Fluorescence and fluorescence-lifetime imaging microscopy (FLIM) to characterize yeast strains by autofluorescence

NASA Astrophysics Data System (ADS)

Bhatta, H.; Goldys, E. M.; Ma, J.

2006-02-01

We characterised populations of wild type baking and brewing yeast cells using intrinsic fluorescence and fluorescence lifetime microscopy, in order to obtain quantitative identifiers of different strains. The cell autofluorescence was excited at 405 nm and observed within 440-540 nm range where strong cell to cell variability was observed. The images were analyzed using customised public domain software, which provided information on cell size, intensity and texture-related features. In light of significant diversity of the data, statistical methods were utilized to assess the validity of the proposed quantitative identifiers for strain differentiation. The Kolmogorov-Smirnov test was applied to confirm that empirical distribution functions for size, intensity and entropy for different strains were statistically different. These characteristics were followed with culture age of 24, 48 and 72 h, (the latter corresponding to a stationary growth phase) and size, and to some extent entropy, were found to be independent of age. The fluorescence intensity presented a distinctive evolution with age, different for each of the examined strains. The lifetime analysis revealed a short decay time component of 1.4 ns and a second, longer one with the average value of 3.5 ns and a broad distribution. High variability of lifetime values within cells was observed however a lifetime texture feature in the studied strains was statistically different.

Adaptive statistical iterative reconstruction improves image quality without affecting perfusion CT quantitation in primary colorectal cancer.

PubMed

Prezzi, D; Goh, V; Virdi, S; Mallett, S; Grierson, C; Breen, D J

2017-01-01

To determine the effect of Adaptive Statistical Iterative Reconstruction (ASIR) on perfusion CT (pCT) parameter quantitation and image quality in primary colorectal cancer. Prospective observational study. Following institutional review board approval and informed consent, 32 patients with colorectal adenocarcinoma underwent pCT (100 kV, 150 mA, 120 s acquisition, axial mode). Tumour regional blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface area product (PS) were determined using identical regions-of-interests for ASIR percentages of 0%, 20%, 40%, 60%, 80% and 100%. Image noise, contrast-to-noise ratio (CNR) and pCT parameters were assessed across ASIR percentages. Coefficients of variation (CV), repeated measures analysis of variance (rANOVA) and Spearman' rank order correlation were performed with statistical significance at 5%. With increasing ASIR percentages, image noise decreased by 33% while CNR increased by 61%; peak tumour CNR was greater than 1.5 with 60% ASIR and above. Mean BF, BV, MTT and PS differed by less than 1.8%, 2.9%, 2.5% and 2.6% across ASIR percentages. CV were 4.9%, 4.2%, 3.3% and 7.9%; rANOVA P values: 0.85, 0.62, 0.02 and 0.81 respectively. ASIR improves image noise and CNR without altering pCT parameters substantially.

Gender Differences in Motor Skills of the Overarm Throw

PubMed Central

Gromeier, Michael; Koester, Dirk; Schack, Thomas

2017-01-01

In this cross-sectional study, the qualitative and quantitative throwing performance of male and female athletes (6 to 16 years of age) was analyzed. The goal of this study was to assess whether there were gender based qualitative and quantitative differences in throwing performance of young athletes, throughout three different age bands (childhood, pubescence, and adolescence). Furthermore, we explored whether all components of the throwing movement are equally affected by gender differences. Focus was placed on five essential components of action: trunk, forearm, humerus, stepping, and backswing. Therefore, children and adolescents (N = 96) were invited to throw three times from three different distances, while aiming at a target placed at shoulder height. The participants were aspiring athletes, competitive in the sport handball. For analyzing the quality of movement the component approach of Halverson and Roberton (1984) was used. The throwing accuracy was noted and used to evaluate the quantitative performance of the throwing movement. Throughout three different age bands, no statistically significant difference was found between genders in throwing accuracy, i.e., quantitative performance. Regarding the qualitative evaluation of the throwing movement, male and female athletes differed significantly. The component approach yielded higher scores for male than for female participants. As expected, with increasing age qualitative and quantitative performance of male and female athletes improved. These results suggest that there are gender-specific differences in qualitative throwing performance, but not necessarily in quantitative throwing performance. Exploration shows that differences in the qualitative throwing performance were seen in specific components of action. Male and female athletes demonstrated similar movement patterns in humerus and forearm actions, but differed in trunk, stepping, and backswing actions. PMID:28261142

Human cytomegalovirus and Epstein-Barr virus in etiopathogenesis of apical periodontitis: a systematic review.

PubMed

Jakovljevic, Aleksandar; Andric, Miroslav

2014-01-01

During the last decade, a hypothesis has been established that human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) may be implicated in the pathogenesis of apical periodontitis. The aim of this review was to analyze the available evidence that indicates that HCMV and EBV can actually contribute to the pathogenesis of periapical lesions and to answer the following focused question: is there a relationship between HCMV and EBV DNA and/or RNA detection and the clinical features of human periapical lesions? The literature search covered MEDLINE, Science Citation Index Expanded (SCIexpanded), Scopus, and The Cochrane Library database. Quantitative statistical analysis was performed on the pooled data of HCMV and EBV messenger RNA transcripts in tissues of symptomatic and asymptomatic periapical lesions. The electronic database search yielded 48 hits from PubMed, 197 hits from Scopus, 40 hits from Web of Science, and 1 from the Cochrane Library. Seventeen cross-sectional studies have been included in the final review. The pooled results from quantitative systematic method analysis showed no statistically significant relationship between the presence of HCMV and EBV messenger RNA transcripts (P = .083 and P = .306, respectively) and the clinical features of apical periodontitis. The findings of HCMV and EBV transcripts in apical periodontitis were controversial among the included studies. Herpesviruses were common in symptomatic and large-size periapical lesions, but such results failed to reach statistical significance. Further studies, including those based on an experimental animal model, should provide more data on herpesviruses as a factor in the pathogenesis of periapical inflammation. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Quantitative Reporting Practices in Middle-Grades Research Journals: Lessons to Learn

ERIC Educational Resources Information Center

Capraro, Robert M.; Capraro, Mary Margaret

2009-01-01

This study examines two journals specific to the middles grades where original quantitative empirical articles are published, Research in Middle Level Education and Middle Grades Research Journal to determine what quantitative statistics are used, how they are used, and what study designs are used. Important for those who write for the…

Scientists and Mathematicians Collaborating to Build Quantitative Skills in Undergraduate Science

ERIC Educational Resources Information Center

Rylands, Leanne; Simbag, Vilma; Matthews, Kelly E.; Coady, Carmel; Belward, Shaun

2013-01-01

There is general agreement in Australia and beyond that quantitative skills (QS) in science, the ability to use mathematics and statistics in context, are important for science. QS in the life sciences are becoming ever more important as these sciences become more quantitative. Consequently, undergraduates studying the life sciences require better…

76 FR 55725 - Agency Information Collection Activities: Request for Comments for a New Information Collection

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-08

... statistical surveys that yield quantitative results that can be generalized to the population of study. This... information will not be used for quantitative information collections that are designed to yield reliably... generic mechanisms that are designed to yield quantitative results. The FHWA received no comments in...

Challenge in Enhancing the Teaching and Learning of Variable Measurements in Quantitative Research

ERIC Educational Resources Information Center

Kee, Chang Peng; Osman, Kamisah; Ahmad, Fauziah

2013-01-01

Statistical analysis is one component that cannot be avoided in a quantitative research. Initial observations noted that students in higher education institution faced difficulty analysing quantitative data which were attributed to the confusions of various variable measurements. This paper aims to compare the outcomes of two approaches applied in…

Employing the Gini coefficient to measure participation inequality in treatment-focused Digital Health Social Networks.

PubMed

van Mierlo, Trevor; Hyatt, Douglas; Ching, Andrew T

2016-01-01

Digital Health Social Networks (DHSNs) are common; however, there are few metrics that can be used to identify participation inequality. The objective of this study was to investigate whether the Gini coefficient, an economic measure of statistical dispersion traditionally used to measure income inequality, could be employed to measure DHSN inequality. Quarterly Gini coefficients were derived from four long-standing DHSNs. The combined data set included 625,736 posts that were generated from 15,181 actors over 18,671 days. The range of actors (8-2323), posts (29-28,684), and Gini coefficients (0.15-0.37) varied. Pearson correlations indicated statistically significant associations between number of actors and number of posts (0.527-0.835, p  < .001), and Gini coefficients and number of posts (0.342-0.725, p  < .001). However, the association between Gini coefficient and number of actors was only statistically significant for the addiction networks (0.619 and 0.276, p  < .036). Linear regression models had positive but mixed R 2 results (0.333-0.527). In all four regression models, the association between Gini coefficient and posts was statistically significant ( t  = 3.346-7.381, p  < .002). However, unlike the Pearson correlations, the association between Gini coefficient and number of actors was only statistically significant in the two mental health networks ( t  = -4.305 and -5.934, p  < .000). The Gini coefficient is helpful in measuring shifts in DHSN inequality. However, as a standalone metric, the Gini coefficient does not indicate optimal numbers or ratios of actors to posts, or effective network engagement. Further, mixed-methods research investigating quantitative performance metrics is required.

[Statistical analysis of German radiologic periodicals: developmental trends in the last 10 years].

PubMed

Golder, W

1999-09-01

To identify which statistical tests are applied in German radiological publications, to what extent their use has changed during the last decade, and which factors might be responsible for this development. The major articles published in "ROFO" and "DER RADIOLOGE" during 1988, 1993 and 1998 were reviewed for statistical content. The contributions were classified by principal focus and radiological subspecialty. The methods used were assigned to descriptive, basal and advanced statistics. Sample size, significance level and power were established. The use of experts' assistance was monitored. Finally, we calculated the so-called cumulative accessibility of the publications. 525 contributions were found to be eligible. In 1988, 87% used descriptive statistics only, 12.5% basal, and 0.5% advanced statistics. The corresponding figures in 1993 and 1998 are 62 and 49%, 32 and 41%, and 6 and 10%, respectively. Statistical techniques were most likely to be used in research on musculoskeletal imaging and articles dedicated to MRI. Six basic categories of statistical methods account for the complete statistical analysis appearing in 90% of the articles. ROC analysis is the single most common advanced technique. Authors make increasingly use of statistical experts' opinion and programs. During the last decade, the use of statistical methods in German radiological journals has fundamentally improved, both quantitatively and qualitatively. Presently, advanced techniques account for 20% of the pertinent statistical tests. This development seems to be promoted by the increasing availability of statistical analysis software.

The Impact of an Interactive Statistics Module on Novices' Development of Scientific Process Skills and Attitudes in a First-Semester Research Foundations Course.

PubMed

Marsan, Lynnsay A; D'Arcy, Christina E; Olimpo, Jeffrey T

2016-12-01

Evidence suggests that incorporating quantitative reasoning exercises into existent curricular frameworks within the science, technology, engineering, and mathematics (STEM) disciplines is essential for novices' development of conceptual understanding and process skills in these domains. Despite this being the case, such studies acknowledge that students often experience difficulty in applying mathematics in the context of scientific problems. To address this concern, the present study sought to explore the impact of active demonstrations and critical reading exercises on novices' comprehension of basic statistical concepts, including hypothesis testing, experimental design, and interpretation of research findings. Students first engaged in a highly interactive height activity that served to intuitively illustrate normal distribution, mean, standard deviation, and sample selection criteria. To enforce practical applications of standard deviation and p -value, student teams were subsequently assigned a figure from a peer-reviewed primary research article and instructed to evaluate the trustworthiness of the data. At the conclusion of this exercise, students presented their evaluations to the class for open discussion and commentary. Quantitative assessment of pre- and post-module survey data indicated a statistically significant increase both in students' scientific reasoning and process skills and in their self-reported confidence in understanding the statistical concepts presented in the module. Furthermore, data indicated that the majority of students (>85%) found the module both interesting and helpful in nature. Future studies will seek to develop additional, novel exercises within this area and to evaluate the impact of such modules across a variety of STEM and non-STEM contexts.

The Impact of an Interactive Statistics Module on Novices’ Development of Scientific Process Skills and Attitudes in a First-Semester Research Foundations Course†

PubMed Central

Marsan, Lynnsay A.; D’Arcy, Christina E.; Olimpo, Jeffrey T.

2016-01-01

Evidence suggests that incorporating quantitative reasoning exercises into existent curricular frameworks within the science, technology, engineering, and mathematics (STEM) disciplines is essential for novices’ development of conceptual understanding and process skills in these domains. Despite this being the case, such studies acknowledge that students often experience difficulty in applying mathematics in the context of scientific problems. To address this concern, the present study sought to explore the impact of active demonstrations and critical reading exercises on novices’ comprehension of basic statistical concepts, including hypothesis testing, experimental design, and interpretation of research findings. Students first engaged in a highly interactive height activity that served to intuitively illustrate normal distribution, mean, standard deviation, and sample selection criteria. To enforce practical applications of standard deviation and p-value, student teams were subsequently assigned a figure from a peer-reviewed primary research article and instructed to evaluate the trustworthiness of the data. At the conclusion of this exercise, students presented their evaluations to the class for open discussion and commentary. Quantitative assessment of pre- and post-module survey data indicated a statistically significant increase both in students’ scientific reasoning and process skills and in their self-reported confidence in understanding the statistical concepts presented in the module. Furthermore, data indicated that the majority of students (>85%) found the module both interesting and helpful in nature. Future studies will seek to develop additional, novel exercises within this area and to evaluate the impact of such modules across a variety of STEM and non-STEM contexts. PMID:28101271

[Relationships between workers' interpersonal helping behavior, social supports, job stressors, psychological stress responses, and vigor in manufacturing industry].

PubMed

Horita, Yuji; Otsuka, Yasumasa

2014-01-01

In the NIOSH Generic Job Stress Model, social support is assumed to moderate the relationship between job stressors and stress responses. However, few studies have investigated how to enhance social support in the workplace. The purpose of this study was to explore the relationships between interpersonal helping behavior, social support, job stressors, psychological stress responses, and vigor among Japanese workers. A total of 240 workers in manufacturing companies returned a questionnaire regarding their interpersonal helping behavior, social support, job stressors, psychological stress responses, and vigor (response rate = 96.0%). After excluding 40 participants due to missing responses, data from a total of 200 participants (163 male and 37 female, mean age = 40.3 yr) were used in the final analyses. Interpersonal helping behavior was assessed by the Japanese version of the Organizational Citizenship Behavior Scale. The Brief Job Stress Questionnaire was used to measure job stressors, psychological stress responses, social support, and vigor. Structured equation modeling was performed to examine the relationships between interpersonal helping behavior, social support, job stressors, psychological stress responses, and vigor. Interpersonal helping behavior had a statistically significant negative effect on psychological stress response through increasing social support. However, interpersonal helping behavior had a statistically significant positive effect on psychological stress response through increasing the quantitative workload. Of these two effects, the former was stronger than the latter. In addition, interpersonal helping behavior had a statistically significant positive effect on vigor through increasing social support. Although interpersonal helping behavior, which helps other workers may increase quantitative workload, leading to high levels of psychological stress responses, that same behavior strengthens trust and team spirit among workers and may enhance social support, leading to low levels of psychological stress responses and high levels of vigor. However, reverse causal relationships may also exist, because our study design was cross-sectional.

Clients' satisfaction with quality of childbirth services: A comparative study between public and private facilities in Limuru Sub-County, Kiambu, Kenya.

PubMed

Okumu, Clarice; Oyugi, Boniface

2018-01-01

This study intended to compare the clients' satisfaction with the quality of childbirth services in a private and public facility amongst mothers who have delivered within the last twenty four to seventy hours. This was a cross-sectional comparative research design with both quantitative and qualitative data collection and analysis methods. Data were collected through a focused group discussion guide and structured questionnaire collecting information on clients' satisfaction with quality of childbirth services. The study was conducted amongst women of reproductive age (WRA) between 15-49 years in Tigoni District hospital (public hospital) and Limuru Nursing home (private hospital). For quantitative data we conducted descriptive analysis and Mann-Whitney test using SPSS version 20.0 while qualitative data was manually analyzed manually using thematic analysis. A higher proportion of clients from private facility 98.1% were attended within 0-30 minutes of arrival to the facility as compared to 87% from public facility. The overall mean score showed that the respondents in public facility gave to satisfaction with the services was 4.46 out of a maximum of 5.00 score while private facility gave 4.60. The level of satisfaction amongst respondents in the public facility on pain relief after delivery was statistically significantly higher than the respondents in private facilities (U = 8132.50, p<0.001) while the level of satisfaction amongst respondents in the public facility on functional equipment was statistically significantly higher than the respondents in private facilities (U = 9206.50, p = 0.001). Moreover, level of satisfaction with the way staff responded to questions and concerns during labour and delivery was statistically significantly higher than the respondents in private facilities (U = 9964.50, p = 0.022). In overall, majority of clients from both public and private facilities expressed satisfaction with quality of services from admission till discharge in both public and private facilities and were willing to recommend other to come and deliver in the respective facilities.

Quantitative assessment of apical debris extrusion and intracanal debris in the apical third, using hand instrumentation and three rotary instrumentation systems.

PubMed

H K, Sowmya; T S, Subhash; Goel, Beena Rani; T N, Nandini; Bhandi, Shilpa H

2014-02-01

Decreased apical extrusion of debris and apical one third debris have strong implications for decreased incidence of postoperative inflammation and pain. Thus, the aim of this study was to assess quantitatively the apical extrusion of debris and intracanal debris in the apical third during root canal instrumentation using hand and three different types of rotary instruments. Sixty freshly extracted single rooted human teeth were randomly divided into four groups. Canal preparation was done using step-back with hand instrumentation, crown-down technique with respect to ProTaper and K3, and hybrid technique with LightSpeed LSX. Irrigation was done with NaOCl, EDTA, and normal saline and for final irrigation, EndoVac system was used. The apically extruded debris was collected on the pre-weighed Millipore plastic filter disk and weighed using microbalance. The teeth were submitted to the histological processing. Sections from the apical third were analyzed by a trinocular research microscope that was coupled to a computer where the images were captured and analyzed using image proplus V4.1.0.0 software. The mean weight of extruded debris for each group and intracanal debris in the root canal was statistically analyzed by a Kruskal-Wallis one-way analysis of variance and Mann-Whitney U test. The result showed that, hand instrumentation using K files showed the highest amount of debris extrusion apically when compared to ProTaper, K3 and LightSpeed LSX. The result also showed that there was no statistically significant difference between the groups in relation to presence of intracanal debris in the apical one third. Based on the results, all instrumentation techniques produced debris extrusion. The engine driven Ni-Ti systems extruded significantly less apical debris than hand instrumentation. There was no statistically significant difference between the groups in relation to presence of intracanal debris in the apical one third.

Quantitative Assessment of Apical Debris Extrusion and Intracanal Debris in the Apical Third, Using Hand Instrumentation and Three Rotary Instrumentation Systems

PubMed Central

H.K., Sowmya; T.S., Subhash; Goel, Beena Rani; T.N., Nandini; Bhandi, Shilpa H.

2014-01-01

Introduction: Decreased apical extrusion of debris and apical one third debris have strong implications for decreased incidence of postoperative inflammation and pain. Thus, the aim of this study was to assess quantitatively the apical extrusion of debris and intracanal debris in the apical third during root canal instrumentation using hand and three different types of rotary instruments. Methodology: Sixty freshly extracted single rooted human teeth were randomly divided into four groups. Canal preparation was done using step-back with hand instrumentation, crown-down technique with respect to ProTaper and K3, and hybrid technique with LightSpeed LSX. Irrigation was done with NaOCl, EDTA, and normal saline and for final irrigation, EndoVac system was used. The apically extruded debris was collected on the pre-weighed Millipore plastic filter disk and weighed using microbalance. The teeth were submitted to the histological processing. Sections from the apical third were analyzed by a trinocular research microscope that was coupled to a computer where the images were captured and analyzed using image proplus V4.1.0.0 software. The mean weight of extruded debris for each group and intracanal debris in the root canal was statistically analyzed by a Kruskal-Wallis one-way analysis of variance and Mann-Whitney U test. Results: The result showed that, hand instrumentation using K files showed the highest amount of debris extrusion apically when compared to ProTaper, K3 and LightSpeed LSX. The result also showed that there was no statistically significant difference between the groups in relation to presence of intracanal debris in the apical one third. Conclusion: Based on the results, all instrumentation techniques produced debris extrusion. The engine driven Ni-Ti systems extruded significantly less apical debris than hand instrumentation. There was no statistically significant difference between the groups in relation to presence of intracanal debris in the apical one third. PMID:24701536

Recovery and creative practices in people with severe mental illness: evaluating well-being and social inclusion.

PubMed

Saavedra, Javier; Pérez, Elvira; Crawford, Paul; Arias, Samuel

2018-04-01

This mixed (quantitative-qualitative) study evaluates the impact of an artistic workshop on a group of people with severe mental illness (SMI). This study focuses on the impact of creative practices on well-being and social inclusion outcomes. After participating in a creative workshop, 31 people diagnosed with a SMI completed pre/post-intervention measures, namely, the Warwick-Edinburgh Mental Well-Being Scale and the Social Inclusion questionnaire. It was applied in two-way repeated measures analysis of variance. The statistic Wilcoxon and Kruskal-Wallis were applied for non-parametric data to measure pre/post-test effects and workshop experience effects, respectively. In addition to quantitative measures, one observer participated in each workshop that ran in parallel in order to deepen and triangulate quantitative outcomes. The qualitative and quantitative results show that social inclusion improved in a significant way with an important size effect. Psychological wellbeing increased significantly with a low size effect. In accordance with these results, creative practices with people diagnosed with SMI are recommended. In order to increase the impact of these interventions, it is recommended to utilize public space away from clinical environments and to include people without SMI in creative activities together with SMI patients. Implications for Rehabilitation: Creative practices can significantly improve social inclusions and well-being in people with severe mental illness. Participating in creative workshops helps to elaborate personal meanings and promote recovery. Creative practices in mental health services can challenge professional roles and institutional practices. Participation of people with and without severe mental illness engaged together in artistic activities can decrease public stigma.

Clinical and quantitative analysis of patients with crowned dens syndrome.

PubMed

Takahashi, Teruyuki; Tamura, Masato; Takasu, Toshiaki; Kamei, Satoshi

2017-05-15

Crowned dens syndrome (CDS) is a radioclinical entity defined by calcium deposition on the transverse ligament of atlas (TLA). In this study, the novel semi-quantitative diagnostic criteria for CDS to evaluate the degree of calcification on TLA by cervical CT are proposed. From January 2010 to September 2014, 35 patients who were diagnosed with CDS by cervical CT were adopted as subjects in this study. Based on novel criteria, calcium deposition on TLA was classified into "Stage" and "Grade", to make a score, which was evaluated semi-quantitatively. The correlation between calcification score and CRP level or pain score, and the effects of treatments, such as NSAIDs and corticosteroids, were statistically analyzed. The total calcification score from added "Stage" and "Grade" scores demonstrated a significantly strong and linear correlation with CRP level (R 2 =0.823, **p<0.01). In the multiple comparison test for the treatment effects, significant improvement of the CRP level and pain score were demonstrated after corticosteroid therapy (**p<0.01) compared with NSAIDs. In the conditional logistic regression analysis, the rapid end of corticosteroid therapy was an independent risk factor for relapse of cervico-occipital pain [OR=50.761, *p=0.0419]. The degree of calcification on TLA evaluated by the novel semi-quantitative criteria significantly correlated with CRP level. In the treatment of CDS, it is recommended that a low dosage (15-30mg) of corticosteroids be used as first-line drugs rather than conventional NSAID therapy. Additionally, it is also recommended to gradually decrease the dosage of corticosteroids. Copyright © 2017 Elsevier B.V. All rights reserved.

Quantitative Analysis of Repertoire-Scale Immunoglobulin Properties in Vaccine-Induced B-Cell Responses

DTIC Science & Technology

2017-05-10

repertoire-wide properties. Finally, through 75 the use of appropriate statistical analyses, the repertoire profiles can be quantitatively compared and 76...cell response to eVLP and 503 quantitatively compare GC B-cell repertoires from immunization conditions. We partitioned the 504 resulting clonotype... Quantitative analysis of repertoire-scale immunoglobulin properties in vaccine-induced B-cell responses Ilja V. Khavrutskii1, Sidhartha Chaudhury*1

Refractive index tomograms and dynamic membrane fluctuations of red blood cells from patients with diabetes mellitus.

PubMed

Lee, SangYun; Park, HyunJoo; Kim, Kyoohyun; Sohn, YongHak; Jang, Seongsoo; Park, YongKeun

2017-04-21

In this paper, we present the optical characterisations of diabetic red blood cells (RBCs) in a non-invasive manner employing three-dimensional (3-D) quantitative phase imaging. By measuring 3-D refractive index tomograms and 2-D time-series phase images, the morphological (volume, surface area and sphericity), biochemical (haemoglobin concentration and content) and mechanical (membrane fluctuation) parameters were quantitatively retrieved at the individual cell level. With simultaneous measurements of individual cell properties, systematic correlative analyses on retrieved RBC parameters were also performed. Our measurements show there exist no statistically significant alterations in morphological and biochemical parameters of diabetic RBCs, compared to those of healthy (non-diabetic) RBCs. In contrast, membrane deformability of diabetic RBCs is significantly lower than that of healthy, non-diabetic RBCs. Interestingly, non-diabetic RBCs exhibit strong correlations between the elevated glycated haemoglobin in RBC cytoplasm and decreased cell deformability, whereas diabetic RBCs do not show correlations. Our observations strongly support the idea that slow and irreversible glycation of haemoglobin and membrane proteins of RBCs by hyperglycaemia significantly compromises RBC deformability in diabetic patients.

Making Meaning of MSW Students' Statistical Abilities: The Role of Self-Efficacy and Knowledge-Based Assessment

ERIC Educational Resources Information Center

Mirick, Rebecca G.; Davis, Ashley

2017-01-01

Although statistics and research are key components of social work education, students are often described as reluctant consumers and users of statistics. Self-efficacy theory has been used to understand students' engagement with the statistical knowledge needed for practice. This quantitative study explores the relationship between self-efficacy,…

[Statistical analysis of articles in "Chinese journal of applied physiology" from 1999 to 2008].

PubMed

Du, Fei; Fang, Tao; Ge, Xue-ming; Jin, Peng; Zhang, Xiao-hong; Sun, Jin-li

2010-05-01

To evaluate the academic level and influence of "Chinese Journal of Applied Physiology" through statistical analysis for the fund sponsored articles published in the recent ten years. The articles of "Chinese Journal of Applied Physiology" from 1999 to 2008 were investigated. The number and the percentage of the fund sponsored articles, the fund organization and the author region were quantitatively analyzed by using the literature metrology method. The number of the fund sponsored articles increased unceasingly. The ratio of the fund from local government significantly enhanced in the latter five years. Most of the articles were from institutes located at Beijing, Zhejiang and Tianjin. "Chinese Journal of Applied Physiology" has a fine academic level and social influence.

The resolving power of in vitro genotoxicity assays for cigarette smoke particulate matter.

PubMed

Scott, K; Saul, J; Crooks, I; Camacho, O M; Dillon, D; Meredith, C

2013-06-01

In vitro genotoxicity assays are often used to compare tobacco smoke particulate matter (PM) from different cigarettes. The quantitative aspect of the comparisons requires appropriate statistical methods and replication levels, to support the interpretation in terms of power and significance. This paper recommends a uniform statistical analysis for the Ames test, mouse lymphoma mammalian cell mutation assay (MLA) and the in vitro micronucleus test (IVMNT); involving a hierarchical decision process with respect to slope, fixed effect and single dose comparisons. With these methods, replication levels of 5 (Ames test TA98), 4 (Ames test TA100), 10 (Ames test TA1537), 6 (MLA) and 4 (IVMNT) resolved a 30% difference in PM genotoxicity. Copyright © 2013 Elsevier Ltd. All rights reserved.

QSAR Study of p56lck Protein Tyrosine Kinase Inhibitory Activity of Flavonoid Derivatives Using MLR and GA-PLS

PubMed Central

Fassihi, Afshin; Sabet, Razieh

2008-01-01

Quantitative relationships between molecular structure and p56lck protein tyrosine kinase inhibitory activity of 50 flavonoid derivatives are discovered by MLR and GA-PLS methods. Different QSAR models revealed that substituent electronic descriptors (SED) parameters have significant impact on protein tyrosine kinase inhibitory activity of the compounds. Between the two statistical methods employed, GA-PLS gave superior results. The resultant GA-PLS model had a high statistical quality (R2 = 0.74 and Q2 = 0.61) for predicting the activity of the inhibitors. The models proposed in the present work are more useful in describing QSAR of flavonoid derivatives as p56lck protein tyrosine kinase inhibitors than those provided previously. PMID:19325836

Morphometric Analysis of Chemoreception Organ in Male and Female Ticks (Acari: Ixodidae).

PubMed

Josek, Tanya; Allan, Brian F; Alleyne, Marianne

2018-05-04

The Haller's organ plays a crucial role in a tick's ability to detect hosts. Even though this sensory organ is vital to tick survival, the morphology of this organ is not well understood. The objective of this study was to characterize variation in the morphological components of the Haller's organ of three medically important tick species using quantitative methods. The Haller's organs of Ixodes scapularis Say (Ixodida: Ixodidae) (black-legged tick), Amblyomma americanum (L.) (Ixodida: Ixodidae) (lone star tick), and Dermacentor variabilis (Say) (Ixodida: Ixodidae) (American dog tick) were morphologically analyzed using environmental scanning electron microscopy and geometric morphometrics, and the results were statistically interpreted using canonical variate analysis. Our data reveal significant, quantitative differences in the morphology of the Haller's organ among all three tick species and that in D. variabilis the sensory structure is sexually dimorphic. Studies like this can serve as a quantitative basis for further studies on sensor physiology, behavior, and tick species life history, potentially leading to novel methods for the prevention of tick-borne disease.

High-coverage quantitative proteomics using amine-specific isotopic labeling.

PubMed

Melanson, Jeremy E; Avery, Steven L; Pinto, Devanand M

2006-08-01

Peptide dimethylation with isotopically coded formaldehydes was evaluated as a potential alternative to techniques such as the iTRAQ method for comparative proteomics. The isotopic labeling strategy and custom-designed protein quantitation software were tested using protein standards and then applied to measure proteins levels associated with Alzheimer's disease (AD). The method provided high accuracy (10% error), precision (14% RSD) and coverage (70%) when applied to the analysis of a standard solution of BSA by LC-MS/MS. The technique was then applied to measure protein abundance levels in brain tissue afflicted with AD relative to normal brain tissue. 2-D LC-MS analysis identified 548 unique proteins (p<0.05). Of these, 349 were quantified with two or more peptides that met the statistical criteria used in this study. Several classes of proteins exhibited significant changes in abundance. For example, elevated levels of antioxidant proteins and decreased levels of mitochondrial electron transport proteins were observed. The results demonstrate the utility of the labeling method for high-throughput quantitative analysis.

Fully Automated Quantitative Estimation of Volumetric Breast Density from Digital Breast Tomosynthesis Images: Preliminary Results and Comparison with Digital Mammography and MR Imaging.

PubMed

Pertuz, Said; McDonald, Elizabeth S; Weinstein, Susan P; Conant, Emily F; Kontos, Despina

2016-04-01

To assess a fully automated method for volumetric breast density (VBD) estimation in digital breast tomosynthesis (DBT) and to compare the findings with those of full-field digital mammography (FFDM) and magnetic resonance (MR) imaging. Bilateral DBT images, FFDM images, and sagittal breast MR images were retrospectively collected from 68 women who underwent breast cancer screening from October 2011 to September 2012 with institutional review board-approved, HIPAA-compliant protocols. A fully automated computer algorithm was developed for quantitative estimation of VBD from DBT images. FFDM images were processed with U.S. Food and Drug Administration-cleared software, and the MR images were processed with a previously validated automated algorithm to obtain corresponding VBD estimates. Pearson correlation and analysis of variance with Tukey-Kramer post hoc correction were used to compare the multimodality VBD estimates. Estimates of VBD from DBT were significantly correlated with FFDM-based and MR imaging-based estimates with r = 0.83 (95% confidence interval [CI]: 0.74, 0.90) and r = 0.88 (95% CI: 0.82, 0.93), respectively (P < .001). The corresponding correlation between FFDM and MR imaging was r = 0.84 (95% CI: 0.76, 0.90). However, statistically significant differences after post hoc correction (α = 0.05) were found among VBD estimates from FFDM (mean ± standard deviation, 11.1% ± 7.0) relative to MR imaging (16.6% ± 11.2) and DBT (19.8% ± 16.2). Differences between VDB estimates from DBT and MR imaging were not significant (P = .26). Fully automated VBD estimates from DBT, FFDM, and MR imaging are strongly correlated but show statistically significant differences. Therefore, absolute differences in VBD between FFDM, DBT, and MR imaging should be considered in breast cancer risk assessment.

A quantitative assessment of patient and nurse outcomes of bedside nursing report implementation.

PubMed

Sand-Jecklin, Kari; Sherman, Jay

2014-10-01

To quantify quantitative outcomes of a practice change to a blended form of bedside nursing report. The literature identifies several benefits of bedside nursing shift report. However, published studies have not adequately quantified outcomes related to this process change, having either small or unreported sample sizes or not testing for statistical significance. Quasi-experimental pre- and postimplementation design. Seven medical-surgical units in a large university hospital implemented a blend of recorded and bedside nursing report. Outcomes monitored included patient and nursing satisfaction, patient falls, nursing overtime and medication errors. We found statistically significant improvements postimplementation in four patient survey items specifically impacted by the change to bedside report. Nursing perceptions of report were significantly improved in the areas of patient safety and involvement in care and nurse accountability postimplementation. However, there was a decline in nurse perception that report took a reasonable amount of time after bedside report implementation; contrary to these perceptions, there was no significant increase in nurse overtime. Patient falls at shift change decreased substantially after the implementation of bedside report. An intervening variable during the study period invalidated the comparison of medication errors pre- and postintervention. There was some indication from both patients and nurses that bedside report was not always consistently implemented. Several positive outcomes were documented in relation to the implementation of a blended bedside shift report, with few drawbacks. Nurse attitudes about report at the final data collection were more positive than at the initial postimplementation data collection. If properly implemented, nursing bedside report can result in improved patient and nursing satisfaction and patient safety outcomes. However, managers should involve staff nurses in the implementation process and continue to monitor consistency in report format as well as satisfaction with the process. © 2014 John Wiley & Sons Ltd.

Predicting early signs of dyslexia at a preliterate age by combining behavioral assessment with structural MRI.

PubMed

Kraft, Indra; Schreiber, Jan; Cafiero, Riccardo; Metere, Riccardo; Schaadt, Gesa; Brauer, Jens; Neef, Nicole E; Müller, Bent; Kirsten, Holger; Wilcke, Arndt; Boltze, Johannes; Friederici, Angela D; Skeide, Michael A

2016-12-01

Recent studies suggest that neurobiological anomalies are already detectable in pre-school children with a family history of developmental dyslexia (DD). However, there is a lack of longitudinal studies showing a direct link between those differences at a preliterate age and the subsequent literacy difficulties seen in school. It is also not clear whether the prediction of DD in pre-school children can be significantly improved when considering neurobiological predictors, compared to models based on behavioral literacy precursors only. We recruited 53 pre-reading children either with (N=25) or without a family risk of DD (N=28). Quantitative T1 MNI data and literacy precursor abilities were assessed at kindergarten age. A subsample of 35 children was tested for literacy skills either one or two years later, that is, either in first or second grade. The group comparison of quantitative T1 measures revealed significantly higher T1 intensities in the left anterior arcuate fascicle (AF), suggesting reduced myelin concentration in preliterate children at risk of DD. A logistic regression showed that DD can be predicted significantly better (p=.024) when neuroanatomical differences between groups are used as predictors (80%) compared to a model based on behavioral predictors only (63%). The Wald statistic confirmed that the T1 intensity of the left AF is a statistically significant predictor of DD (p<.05). Our longitudinal results provide evidence for the hypothesis that neuroanatomical anomalies in children with a family risk of DD are related to subsequent problems in acquiring literacy. Particularly, solid white matter organization in the left anterior arcuate fascicle seems to play a pivotal role. Copyright © 2016 Elsevier Inc. All rights reserved.

Using a Standardized Clinical Quantitative Sensory Testing Battery to Judge the Clinical Relevance of Sensory Differences Between Adjacent Body Areas.

PubMed

Dimova, Violeta; Oertel, Bruno G; Lötsch, Jörn

2017-01-01

Skin sensitivity to sensory stimuli varies among different body areas. A standardized clinical quantitative sensory testing (QST) battery, established for the diagnosis of neuropathic pain, was used to assess whether the magnitude of differences between test sites reaches clinical significance. Ten different sensory QST measures derived from thermal and mechanical stimuli were obtained from 21 healthy volunteers (10 men) and used to create somatosensory profiles bilateral from the dorsum of the hands (the standard area for the assessment of normative values for the upper extremities as proposed by the German Research Network on Neuropathic Pain) and bilateral at volar forearms as a neighboring nonstandard area. The parameters obtained were statistically compared between test sites. Three of the 10 QST parameters differed significantly with respect to the "body area," that is, warmth detection, thermal sensory limen, and mechanical pain thresholds. After z-transformation and interpretation according to the QST battery's standard instructions, 22 abnormal values were obtained at the hand. Applying the same procedure to parameters assessed at the nonstandard site forearm, that is, z-transforming them to the reference values for the hand, 24 measurements values emerged as abnormal, which was not significantly different compared with the hand (P=0.4185). Sensory differences between neighboring body areas are statistically significant, reproducing prior knowledge. This has to be considered in scientific assessments where a small variation of the tested body areas may not be an option. However, the magnitude of these differences was below the difference in sensory parameters that is judged as abnormal, indicating a robustness of the QST instrument against protocol deviations with respect to the test area when using the method of comparison with a 95 % confidence interval of a reference dataset.

[A comparison of convenience sampling and purposive sampling].

PubMed

Suen, Lee-Jen Wu; Huang, Hui-Man; Lee, Hao-Hsien

2014-06-01

Convenience sampling and purposive sampling are two different sampling methods. This article first explains sampling terms such as target population, accessible population, simple random sampling, intended sample, actual sample, and statistical power analysis. These terms are then used to explain the difference between "convenience sampling" and purposive sampling." Convenience sampling is a non-probabilistic sampling technique applicable to qualitative or quantitative studies, although it is most frequently used in quantitative studies. In convenience samples, subjects more readily accessible to the researcher are more likely to be included. Thus, in quantitative studies, opportunity to participate is not equal for all qualified individuals in the target population and study results are not necessarily generalizable to this population. As in all quantitative studies, increasing the sample size increases the statistical power of the convenience sample. In contrast, purposive sampling is typically used in qualitative studies. Researchers who use this technique carefully select subjects based on study purpose with the expectation that each participant will provide unique and rich information of value to the study. As a result, members of the accessible population are not interchangeable and sample size is determined by data saturation not by statistical power analysis.

Large-Scale Quantitative Analysis of Painting Arts

PubMed Central

Kim, Daniel; Son, Seung-Woo; Jeong, Hawoong

2014-01-01

Scientists have made efforts to understand the beauty of painting art in their own languages. As digital image acquisition of painting arts has made rapid progress, researchers have come to a point where it is possible to perform statistical analysis of a large-scale database of artistic paints to make a bridge between art and science. Using digital image processing techniques, we investigate three quantitative measures of images – the usage of individual colors, the variety of colors, and the roughness of the brightness. We found a difference in color usage between classical paintings and photographs, and a significantly low color variety of the medieval period. Interestingly, moreover, the increment of roughness exponent as painting techniques such as chiaroscuro and sfumato have advanced is consistent with historical circumstances. PMID:25501877

[Instruments for quantitative methods of nursing research].

PubMed

Vellone, E

2000-01-01

Instruments for quantitative nursing research are a mean to objectify and measure a variable or a phenomenon in the scientific research. There are direct instruments to measure concrete variables and indirect instruments to measure abstract concepts (Burns, Grove, 1997). Indirect instruments measure the attributes by which a concept is made of. Furthermore, there are instruments for physiologic variables (e.g. for the weight), observational instruments (Check-lists e Rating Scales), interviews, questionnaires, diaries and the scales (Check-lists, Rating Scales, Likert Scales, Semantic Differential Scales e Visual Anologue Scales). The choice to select an instrument or another one depends on the research question and design. Instruments research are very useful in research both to describe the variables and to see statistical significant relationships. Very carefully should be their use in the clinical practice for diagnostic assessment.

Experimental design and data-analysis in label-free quantitative LC/MS proteomics: A tutorial with MSqRob.

PubMed

Goeminne, Ludger J E; Gevaert, Kris; Clement, Lieven

2018-01-16

Label-free shotgun proteomics is routinely used to assess proteomes. However, extracting relevant information from the massive amounts of generated data remains difficult. This tutorial provides a strong foundation on analysis of quantitative proteomics data. We provide key statistical concepts that help researchers to design proteomics experiments and we showcase how to analyze quantitative proteomics data using our recent free and open-source R package MSqRob, which was developed to implement the peptide-level robust ridge regression method for relative protein quantification described by Goeminne et al. MSqRob can handle virtually any experimental proteomics design and outputs proteins ordered by statistical significance. Moreover, its graphical user interface and interactive diagnostic plots provide easy inspection and also detection of anomalies in the data and flaws in the data analysis, allowing deeper assessment of the validity of results and a critical review of the experimental design. Our tutorial discusses interactive preprocessing, data analysis and visualization of label-free MS-based quantitative proteomics experiments with simple and more complex designs. We provide well-documented scripts to run analyses in bash mode on GitHub, enabling the integration of MSqRob in automated pipelines on cluster environments (https://github.com/statOmics/MSqRob). The concepts outlined in this tutorial aid in designing better experiments and analyzing the resulting data more appropriately. The two case studies using the MSqRob graphical user interface will contribute to a wider adaptation of advanced peptide-based models, resulting in higher quality data analysis workflows and more reproducible results in the proteomics community. We also provide well-documented scripts for experienced users that aim at automating MSqRob on cluster environments. Copyright © 2017 Elsevier B.V. All rights reserved.

Simulated linear test applied to quantitative proteomics.

PubMed

Pham, T V; Jimenez, C R

2016-09-01

Omics studies aim to find significant changes due to biological or functional perturbation. However, gene and protein expression profiling experiments contain inherent technical variation. In discovery proteomics studies where the number of samples is typically small, technical variation plays an important role because it contributes considerably to the observed variation. Previous methods place both technical and biological variations in tightly integrated mathematical models that are difficult to adapt for different technological platforms. Our aim is to derive a statistical framework that allows the inclusion of a wide range of technical variability. We introduce a new method called the simulated linear test, or the s-test, that is easy to implement and easy to adapt for different models of technical variation. It generates virtual data points from the observed values according to a pre-defined technical distribution and subsequently employs linear modeling for significance analysis. We demonstrate the flexibility of the proposed approach by deriving a new significance test for quantitative discovery proteomics for which missing values have been a major issue for traditional methods such as the t-test. We evaluate the result on two label-free (phospho) proteomics datasets based on ion-intensity quantitation. Available at http://www.oncoproteomics.nl/software/stest.html : t.pham@vumc.nl. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Quantitative profiling of CpG island methylation in human stool for colorectal cancer detection.

PubMed

Elliott, Giles O; Johnson, Ian T; Scarll, Jane; Dainty, Jack; Williams, Elizabeth A; Garg, D; Coupe, Amanda; Bradburn, David M; Mathers, John C; Belshaw, Nigel J

2013-01-01

The aims of this study were to investigate the use of quantitative CGI methylation data from stool DNA to classify colon cancer patients and to relate stool CGI methylation levels to those found in corresponding tissue samples. We applied a quantitative methylation-specific PCR assay to determine CGI methylation levels of six genes, previously shown to be aberrantly methylated during colorectal carcinogenesis. Assays were performed on DNA from biopsies of "normal" mucosa and stool samples from 57 patients classified as disease-free, adenoma, or cancer by endoscopy, and in tumour tissue from cancer patients. Additionally, CGI methylation was analysed in stool DNA from an asymptomatic population of individuals covering a broad age range (mean = 47 ± 24 years) CGI methylation levels in stool DNA were significantly higher than in DNA from macroscopically normal mucosa, and a significant correlation between stool and mucosa was observed for ESR1 only. Multivariate statistical analyses using the methylation levels of each CGI in stool DNA as a continuous variable revealed a highly significant (p = 0.003) classification of cancer vs. non-cancer (adenoma + disease-free) patients (sensitivity = 65 %, specificity = 81 %). CGI methylation profiling of stool DNA successfully identified patients with cancer despite the methylation status of CGIs in stool DNA not generally reflecting those in DNA from the colonic mucosa.

Robot-assisted gait training versus treadmill training in patients with Parkinson's disease: a kinematic evaluation with gait profile score.

PubMed

Galli, M; Cimolin, V; De Pandis, M F; Le Pera, D; Sova, I; Albertini, G; Stocchi, F; Franceschini, M

2016-01-01

The purpose of this study was to quantitatively compare the effects, on walking performance, of end-effector robotic rehabilitation locomotor training versus intensive training with a treadmill in Parkinson's disease (PD). Fifty patients with PD were randomly divided into two groups: 25 were assigned to the robot-assisted therapy group (RG) and 25 to the intensive treadmill therapy group (IG). They were evaluated with clinical examination and 3D quantitative gait analysis [gait profile score (GPS) and its constituent gait variable scores (GVSs) were calculated from gait analysis data] at the beginning (T0) and at the end (T1) of the treatment. In the RG no differences were found in the GPS, but there were significant improvements in some GVSs (Pelvic Obl and Hip Ab-Add). The IG showed no statistically significant changes in either GPS or GVSs. The end-effector robotic rehabilitation locomotor training improved gait kinematics and seems to be effective for rehabilitation in patients with mild PD.

Relationship of the Interaction Between Two Quantitative Trait Loci with γ-Globin Expression in β-Thalassemia Intermedia Patients.

PubMed

NickAria, Shiva; Haghpanah, Sezaneh; Ramzi, Mani; Karimi, Mehran

2018-05-10

Globin switching is a significant factor on blood hemoglobin (Hb) level but its molecular mechanisms have not yet been identified, however, several quantitative trait loci (QTL) and polymorphisms involved regions on chromosomes 2p, 6q, 8q and X account for variation in the γ-globin expression level. We studied the effect of interaction between a region on intron six of the TOX gene, chromosome 8q (chr8q) and XmnI locus on the γ-globin promoter, chr11p on γ-globin expression in 150 β-thalassemia intermedia (β-TI) patients, evaluated by statistical interaction analysis. Our results showed a significant interaction between one QTL on intron six of the TOX gene (rs9693712) and XmnI locus that effect γ-globin expression. Interchromosomal interaction mediates through transcriptional machanisms to preserve true genome architectural features, chromosomes localization and DNA bending. This interaction can be a part of the unknown molecular mechanism of globin switching and regulation of gene expression.

Assessing Aircraft Supply Air to Recommend Compounds for Timely Warning of Contamination

NASA Astrophysics Data System (ADS)

Fox, Richard B.

Taking aircraft out of service for even one day to correct fume-in-cabin events can cost the industry roughly $630 million per year in lost revenue. The quantitative correlation study investigated quantitative relationships between measured concentrations of contaminants in bleed air and probability of odor detectability. Data were collected from 94 aircraft engine and auxiliary power unit (APU) bleed air tests from an archival data set between 1997 and 2011, and no relationships were found. Pearson correlation was followed by regression analysis for individual contaminants. Significant relationships of concentrations of compounds in bleed air to probability of odor detectability were found (p<0.05), as well as between compound concentration and probability of sensory irritancy detectability. Study results may be useful to establish early warning levels. Predictive trend monitoring, a method to identify potential pending failure modes within a mechanical system, may influence scheduled down-time for maintenance as a planned event, rather than repair after a mechanical failure and thereby reduce operational costs associated with odor-in-cabin events. Twenty compounds (independent variables) were found statistically significant as related to probability of odor detectability (dependent variable 1). Seventeen compounds (independent variables) were found statistically significant as related to probability of sensory irritancy detectability (dependent variable 2). Additional research was recommended to further investigate relationships between concentrations of contaminants and probability of odor detectability or probability of sensory irritancy detectability for all turbine oil brands. Further research on implementation of predictive trend monitoring may be warranted to demonstrate how the monitoring process might be applied to in-flight application.

Characterizing trabecular bone structure for assessing vertebral fracture risk on volumetric quantitative computed tomography

NASA Astrophysics Data System (ADS)

Nagarajan, Mahesh B.; Checefsky, Walter A.; Abidin, Anas Z.; Tsai, Halley; Wang, Xixi; Hobbs, Susan K.; Bauer, Jan S.; Baum, Thomas; Wismüller, Axel

2015-03-01

While the proximal femur is preferred for measuring bone mineral density (BMD) in fracture risk estimation, the introduction of volumetric quantitative computed tomography has revealed stronger associations between BMD and spinal fracture status. In this study, we propose to capture properties of trabecular bone structure in spinal vertebrae with advanced second-order statistical features for purposes of fracture risk assessment. For this purpose, axial multi-detector CT (MDCT) images were acquired from 28 spinal vertebrae specimens using a whole-body 256-row CT scanner with a dedicated calibration phantom. A semi-automated method was used to annotate the trabecular compartment in the central vertebral slice with a circular region of interest (ROI) to exclude cortical bone; pixels within were converted to values indicative of BMD. Six second-order statistical features derived from gray-level co-occurrence matrices (GLCM) and the mean BMD within the ROI were then extracted and used in conjunction with a generalized radial basis functions (GRBF) neural network to predict the failure load of the specimens; true failure load was measured through biomechanical testing. Prediction performance was evaluated with a root-mean-square error (RMSE) metric. The best prediction performance was observed with GLCM feature `correlation' (RMSE = 1.02 ± 0.18), which significantly outperformed all other GLCM features (p < 0.01). GLCM feature correlation also significantly outperformed MDCTmeasured mean BMD (RMSE = 1.11 ± 0.17) (p< 10-4). These results suggest that biomechanical strength prediction in spinal vertebrae can be significantly improved through characterization of trabecular bone structure with GLCM-derived texture features.

Quantitative structure-retention relationships of polycyclic aromatic hydrocarbons gas-chromatographic retention indices.

PubMed

Drosos, Juan Carlos; Viola-Rhenals, Maricela; Vivas-Reyes, Ricardo

2010-06-25

Polycyclic aromatic compounds (PAHs) are of concern in environmental chemistry and toxicology. In the present work, a QSRR study was performed for 209 previously reported PAHs using quantum mechanics and other sources descriptors estimated by different approaches. The B3LYP/6-31G* level of theory was used for geometrical optimization and quantum mechanics related variables. A good linear relationship between gas-chromatographic retention index and electronic or topologic descriptors was found by stepwise linear regression analysis. The molecular polarizability (alpha) and the second order molecular connectivity Kier and Hall index ((2)chi) showed evidence of significant correlation with retention index by means of important squared coefficient of determination, (R(2)), values (R(2)=0.950 and 0.962, respectively). A one variable QSRR model is presented for each descriptor and both models demonstrates a significant predictive capacity established using the leave-many-out LMO (excluding 25% of rows) cross validation method's q(2) cross-validation coefficients q(2)(CV-LMO25%), (obtained q(2)(CV-LMO25%) 0.947 and 0.960, respectively). Furthermore, the physicochemical interpretation of selected descriptors allowed detailed explanation of the source of the observed statistical correlation. The model analysis suggests that only one descriptor is sufficient to establish a consistent retention index-structure relationship. Moderate or non-significant improve was observed for quantitative results or statistical validation parameters when introducing more terms in predictive equation. The one parameter QSRR proposed model offers a consistent scheme to predict chromatographic properties of PAHs compounds. Copyright 2010 Elsevier B.V. All rights reserved.

Attitudes about high school physics in relationship to gender and ethnicity: A mixed method analysis

NASA Astrophysics Data System (ADS)

Hafza, Rabieh Jamal

There is an achievement gap and lack of participation in science, technology, engineering, and math (STEM) by minority females. The number of minority females majoring in STEM related fields and earning advanced degrees in these fields has not significantly increased over the past 40 years. Previous research has evaluated the relationship between self-identity concept and factors that promote the academic achievement as well the motivation of students to study different subject areas. This study examined the interaction between gender and ethnicity in terms of physics attitudes in the context of real world connections, personal interest, sense making/effort, problem solving confidence, and problem solving sophistication. The Colorado Learning Attitudes about Science Survey (CLASS) was given to 131 students enrolled in physics classes. There was a statistically significant Gender*Ethnicity interaction for attitude in the context of Real World Connections, Personal Interest, Sense Making/Effort, Problem Solving Confidence, and Problem Solving Sophistication as a whole. There was also a statistically significant Gender*Ethnicity interaction for attitude in the context of Real World Connections, Personal Interest, and Sense Making/Effort individually. Five Black females were interviewed to triangulate the quantitative results and to describe the experiences of minority females taking physics classes. There were four themes that emerged from the interviews and supported the findings from the quantitative results. The data supported previous research done on attitudes about STEM. The results reported that Real World Connections and Personal Interest could be possible factors that explain the lack of participation and achievement gaps that exists among minority females.

Factors Influencing Academic Performance in Quantitative Courses among Undergraduate Business Students of a Public Higher Education Institution

ERIC Educational Resources Information Center

Yousef, Darwish Abdulrahamn

2017-01-01

Purpose: This paper aims to investigate the impacts of teaching style, English language and communication and assessment methods on the academic performance of undergraduate business students in introductory quantitative courses such as Statistics for Business 1 and 2, Quantitative Methods for Business, Operations and Production Management and…

Gender, Math Confidence, and Grit: Relationships with Quantitative Skills and Performance in an Undergraduate Biology Course

ERIC Educational Resources Information Center

Flanagan, K. M.; Einarson, J.

2017-01-01

In a world filled with big data, mathematical models, and statistics, the development of strong quantitative skills is becoming increasingly critical for modern biologists. Teachers in this field must understand how students acquire quantitative skills and explore barriers experienced by students when developing these skills. In this study, we…

Low-frequency quantitative ultrasound imaging of cell death in vivo

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

Sadeghi-Naini, Ali; Falou, Omar; Czarnota, Gregory J.

Purpose: Currently, no clinical imaging modality is used routinely to assess tumor response to cancer therapies within hours to days of the delivery of treatment. Here, the authors demonstrate the efficacy of ultrasound at a clinically relevant frequency to quantitatively detect changes in tumors in response to cancer therapies using preclinical mouse models.Methods: Conventional low-frequency and corresponding high-frequency ultrasound (ranging from 4 to 28 MHz) were used along with quantitative spectroscopic and signal envelope statistical analyses on data obtained from xenograft tumors treated with chemotherapy, x-ray radiation, as well as a novel vascular targeting microbubble therapy.Results: Ultrasound-based spectroscopic biomarkers indicatedmore » significant changes in cell-death associated parameters in responsive tumors. Specifically changes in the midband fit, spectral slope, and 0-MHz intercept biomarkers were investigated for different types of treatment and demonstrated cell-death related changes. The midband fit and 0-MHz intercept biomarker derived from low-frequency data demonstrated increases ranging approximately from 0 to 6 dBr and 0 to 8 dBr, respectively, depending on treatments administrated. These data paralleled results observed for high-frequency ultrasound data. Statistical analysis of ultrasound signal envelope was performed as an alternative method to obtain histogram-based biomarkers and provided confirmatory results. Histological analysis of tumor specimens indicated up to 61% cell death present in the tumors depending on treatments administered, consistent with quantitative ultrasound findings indicating cell death. Ultrasound-based spectroscopic biomarkers demonstrated a good correlation with histological morphological findings indicative of cell death (r{sup 2}= 0.71, 0.82; p < 0.001).Conclusions: In summary, the results provide preclinical evidence, for the first time, that quantitative ultrasound used at a clinically relevant frequency, in addition to high-frequency ultrasound, can detect tissue changes associated with cell death in vivo in response to cancer treatments.« less

Comparison among Reconstruction Algorithms for Quantitative Analysis of 11C-Acetate Cardiac PET Imaging.

PubMed

Shi, Ximin; Li, Nan; Ding, Haiyan; Dang, Yonghong; Hu, Guilan; Liu, Shuai; Cui, Jie; Zhang, Yue; Li, Fang; Zhang, Hui; Huo, Li

2018-01-01

Kinetic modeling of dynamic 11 C-acetate PET imaging provides quantitative information for myocardium assessment. The quality and quantitation of PET images are known to be dependent on PET reconstruction methods. This study aims to investigate the impacts of reconstruction algorithms on the quantitative analysis of dynamic 11 C-acetate cardiac PET imaging. Suspected alcoholic cardiomyopathy patients ( N = 24) underwent 11 C-acetate dynamic PET imaging after low dose CT scan. PET images were reconstructed using four algorithms: filtered backprojection (FBP), ordered subsets expectation maximization (OSEM), OSEM with time-of-flight (TOF), and OSEM with both time-of-flight and point-spread-function (TPSF). Standardized uptake values (SUVs) at different time points were compared among images reconstructed using the four algorithms. Time-activity curves (TACs) in myocardium and blood pools of ventricles were generated from the dynamic image series. Kinetic parameters K 1 and k 2 were derived using a 1-tissue-compartment model for kinetic modeling of cardiac flow from 11 C-acetate PET images. Significant image quality improvement was found in the images reconstructed using iterative OSEM-type algorithms (OSME, TOF, and TPSF) compared with FBP. However, no statistical differences in SUVs were observed among the four reconstruction methods at the selected time points. Kinetic parameters K 1 and k 2 also exhibited no statistical difference among the four reconstruction algorithms in terms of mean value and standard deviation. However, for the correlation analysis, OSEM reconstruction presented relatively higher residual in correlation with FBP reconstruction compared with TOF and TPSF reconstruction, and TOF and TPSF reconstruction were highly correlated with each other. All the tested reconstruction algorithms performed similarly for quantitative analysis of 11 C-acetate cardiac PET imaging. TOF and TPSF yielded highly consistent kinetic parameter results with superior image quality compared with FBP. OSEM was relatively less reliable. Both TOF and TPSF were recommended for cardiac 11 C-acetate kinetic analysis.

Middle school science curriculum design and 8th grade student achievement in Massachusetts public schools

NASA Astrophysics Data System (ADS)

Clifford, Betsey A.

The Massachusetts Department of Elementary and Secondary Education (DESE) released proposed Science and Technology/Engineering standards in 2013 outlining the concepts that should be taught at each grade level. Previously, standards were in grade spans and each district determined the method of implementation. There are two different methods used teaching middle school science: integrated and discipline-based. In the proposed standards, the Massachusetts DESE uses grade-by-grade standards using an integrated approach. It was not known if there is a statistically significant difference in student achievement on the 8th grade science MCAS assessment for students taught with an integrated or discipline-based approach. The results on the 8th grade science MCAS test from six public school districts from 2010 -- 2013 were collected and analyzed. The methodology used was quantitative. Results of an ANOVA showed that there was no statistically significant difference in overall student achievement between the two curriculum models. Furthermore, there was no statistically significant difference for the various domains: Earth and Space Science, Life Science, Physical Science, and Technology/Engineering. This information is useful for districts hesitant to make the change from a discipline-based approach to an integrated approach. More research should be conducted on this topic with a larger sample size to better support the results.

Effects of rinsing with arginine bicarbonate and urea solutions on initial enamel lesions in situ.

PubMed

Yu, Y; Wang, X; Ge, C; Wang, B; Cheng, C; Gan, Y-H

2017-04-01

The aim of this study was to investigate the effects of rinsing with arginine or urea solution on initial enamel lesions in situ. Fourteen subjects who wore mandibular removable partial dentures embedded with bovine enamel blocks with artificial enamel lesions were included. The experiment included four 4-week rinsing periods with a 10-day washout period between each rinsing period. In each rinsing period, the subjects rinsed after meal or snack using water, or 2% arginine bicarbonate, or 1% urea, or 0.05% NaF solution, five times daily. The mineralization changes of the enamel lesions were assessed using quantitative light-induced fluorescence. All groups except the water group showed a statistically significant decrease in the fluorescence loss after treatment, compared with their respective baseline. Although both the arginine group and urea group showed more decrease in fluorescence loss than that of the water group, the decrease was not statistically significantly different from that of the water group. The decrease in fluorescence loss of the NaF group was statistically significant than that of the water group, arginine group, and urea group. Rinsing with arginine or urea solution offers limited remineralizing benefit to enamel lesions over a period of 4-week time. © 2016 The Authors. Oral Diseases Published by John Wiley & Sons Ltd.

Risk management in inpatient units in the Czech Republic from the point of view of nurses in leadership positions.

PubMed

Prokešová, Radka; Brabcová, Iva; Pokojová, Radka; Bártlová, Sylva

2016-12-01

The goal of this study was to assess specific features of risk management from the point of view of nurses in leadership positions in inpatient units in Czech hospitals. The study was performed using a quantitative research strategy, i.e., a questionnaire. The data sample was analyzed using SPSS v. 23.0. Pearson's chi-square and analysis of adjusted residues were used for identifying the existence associations of nominal and/or ordinal quantities. 315 nurses in leadership positions working in inpatient units of Czech hospitals were included in the sample. The sample was created using random selection by means of quotas. Based on the study results, statistically significant relations between the respondents' education and the utilization of methods to identify risks were identified. Furthermore, statistically significant relationships were found between a nurse's functional role within the system and regular analysis and evaluation of risks and between the type of the healthcare facility and the degree of patient involvement in risk management. The study found statistically significant correlations that can be used to increase the effectiveness of risk management in inpatient units of Czech hospitals. From this perspective, the fact that patient involvement in risk management was only reported by 37.8% of respondents seems to be the most notable problem.

Prognostic value of GLUT-1 expression in ovarian surface epithelial tumors: a morphometric study.

PubMed

Ozcan, Ayhan; Deveci, Mehmet Salih; Oztas, Emin; Dede, Murat; Yenen, Mufit Cemal; Korgun, Emin Turkay; Gunhan, Omer

2005-08-01

To investigate the reported increase in the expression of the glucose transporter GLUT-1 in borderline and malignant ovarian epithelial tumors and its relationship to prognosis. In this study, areas in which immunohistochemical membranous staining with GLUT-1 were most evident were selected, and the proportions of GLUT-1 expression in 46 benign, 11 borderline and 42 malignant cases of ovarian epithelial tumors were determined quantitatively with a computer and Zeiss Vision KS 400 3.0 (Göttingen, Germany) for Windows (Microsoft, Redmond, Washington, U.S.A.) image analysis. GLUT-1 expression was determined in all borderline tumors (11 of 11) and in 97.6% of malignant tumors (41 of 42). No GLUT-1 expression was observed in benign tumors. The intensity of GLUT-1 staining was lower in borderline tumors than in malignant cases. This was statistically significant (p = 0.005). As differentiation in malignant tumors increased, proportions of GLUT-1 expression showed a relative increase, but this difference was not statistically significant (p = 0.68). When GLUT-1 expression in borderline and malignant ovarian epithelial tumors was analyzed against prognosis, no statistically significant difference was identified. Assessment of GLUT-1 expression using the image analysis program was more reliable, with higher reproducibility than in previous studies.

Comparative evaluation of the effect of denture cleansers on the surface topography of denture base materials: An in-vitro study

PubMed Central

Jeyapalan, Karthigeyan; Kumar, Jaya Krishna; Azhagarasan, N. S.

2015-01-01

Aims: The aim was to evaluate and compare the effects of three chemically different commercially available denture cleansing agents on the surface topography of two different denture base materials. Materials and Methods: Three chemically different denture cleansers (sodium perborate, 1% sodium hypochlorite, 0.2% chlorhexidine gluconate) were used on two denture base materials (acrylic resin and chrome cobalt alloy) and the changes were evaluated at 3 times intervals (56 h, 120 h, 240 h). Changes from baseline for surface roughness were recorded using a surface profilometer and standard error of the mean (SEM) both quantitatively and qualitatively, respectively. Qualitative surface analyses for all groups were done by SEM. Statistical Analysis Used: The values obtained were analyzed statistically using one-way ANOVA and paired t-test. Results: All three denture cleanser solutions showed no statistically significant surface changes on the acrylic resin portions at 56 h, 120 h, and 240 h of immersion. However, on the alloy portion changes were significant at the end of 120 h and 240 h. Conclusion: Of the three denture cleansers used in the study, none produced significant changes on the two denture base materials for the short duration of immersion, whereas changes were seen as the immersion periods were increased. PMID:26538915

EVALUATION OF FACTORS IN THE ELUTION OF HYDROCORTISONE FROM PAPER CHROMATOGRAMS

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

Ganis, F.M.; Hendrickson, M.W.; Giunta, P.D.

An assessment was made of a number of variable factors which affect the recovery of hydrocortisone from eluted filter paper chromatographic fractions. Factors tested included time of elution, sample concentration, rinsing of eluting fractions and pre-washing of the filter paper. It was noted that a 50 mu g sample could be quantitatively recovered after a 15-minute elution time from a pre-washed filter paper fraction. The results were subjected to a statistical analysis and were found to be highly significant. (auth)

Quantitative analysis of drainage obtained from aerial photographs and RBV/LANDSAT images

NASA Technical Reports Server (NTRS)

Dejesusparada, N. (Principal Investigator); Formaggio, A. R.; Epiphanio, J. C. N.; Filho, M. V.

1981-01-01

Data obtained from aerial photographs (1:60,000) and LANDSAT return beam vidicon imagery (1:100,000) concerning drainage density, drainage texture, hydrography density, and the average length of channels were compared. Statistical analysis shows that significant differences exist in data from the two sources. The highly drained area lost more information than the less drained area. In addition, it was observed that the loss of information about the number of rivers was higher than that about the length of the channels.

Interpretation of the rainbow color scale for quantitative medical imaging: perceptually linear color calibration (CSDF) versus DICOM GSDF

NASA Astrophysics Data System (ADS)

Chesterman, Frédérique; Manssens, Hannah; Morel, Céline; Serrell, Guillaume; Piepers, Bastian; Kimpe, Tom

2017-03-01

Medical displays for primary diagnosis are calibrated to the DICOM GSDF1 but there is no accepted standard today that describes how display systems for medical modalities involving color should be calibrated. Recently the Color Standard Display Function3,4 (CSDF), a calibration using the CIEDE2000 color difference metric to make a display as perceptually linear as possible has been proposed. In this work we present the results of a first observer study set up to investigate the interpretation accuracy of a rainbow color scale when a medical display is calibrated to CSDF versus DICOM GSDF and a second observer study set up to investigate the detectability of color differences when a medical display is calibrated to CSDF, DICOM GSDF and sRGB. The results of the first study indicate that the error when interpreting a rainbow color scale is lower for CSDF than for DICOM GSDF with statistically significant difference (Mann-Whitney U test) for eight out of twelve observers. The results correspond to what is expected based on CIEDE2000 color differences between consecutive colors along the rainbow color scale for both calibrations. The results of the second study indicate a statistical significant improvement in detecting color differences when a display is calibrated to CSDF compared to DICOM GSDF and a (non-significant) trend indicating improved detection for CSDF compared to sRGB. To our knowledge this is the first work that shows the added value of a perceptual color calibration method (CSDF) in interpreting medical color images using the rainbow color scale. Improved interpretation of the rainbow color scale may be beneficial in the area of quantitative medical imaging (e.g. PET SUV, quantitative MRI and CT and doppler US), where a medical specialist needs to interpret quantitative medical data based on a color scale and/or detect subtle color differences and where improved interpretation accuracy and improved detection of color differences may contribute to a better diagnosis. Our results indicate that for diagnostic applications involving both grayscale and color images, CSDF should be chosen over DICOM GSDF and sRGB as it assures excellent detection for color images and at the same time maintains DICOM GSDF for grayscale images.

Migration and common mental disorder: an improvement in mental health over time?

PubMed

Butler, Margaret; Warfa, Nasir; Khatib, Yasmin; Bhui, Kamaldeep

2015-02-01

Global migration is reaching record high levels and UK migrant groups comprise an increasing proportion of the total population. The migratory process causes stress that can affect mental health. There is limited consistent empirical evidence of a longitudinal nature to explain the association between migration and mental health. This review aims to examine the evidence of a relationship between migration and common mental disorder (CMD) amongst migrants over time. A comprehensive search of medical and psychiatric databases for global quantitative empirical studies investigating incidence of CMD amongst adult migrants from 1975 to July 2012 was conducted. Declines in rates of CMD amongst migrants over time were reported by two thirds of the 18 studies reviewed, less than one third of which were statistically significant. On the contrary, three studies showed an increased rate of CMD, one statistically significant. Individual psychological resources, social support, the acculturation process, cultural variations and time since relocation are identified as statistically significant protective factors against the development of CMD amongst migrants. New enlightening points include the significant impact of varying patterns of psychological distress, of which negative is the most adverse for CMD. Migration is an extremely complex process. Further clarification is needed to gain deeper understanding of the relationship between migration and CMD to address contradictions in the literature and health inequalities amongst migrants.

Self-efficacy, stress, and acculturation as predictors of first year science success among Latinos at a South Texas university

NASA Astrophysics Data System (ADS)

McNamara, Mark W.

The study tested the hypothesis that self-efficacy, stress, and acculturation are useful predictors of academic achievement in first year university science, independent of high school GPA and SAT scores, in a sample of Latino students at a South Texas Hispanic serving institution of higher education. The correlational study employed a mixed methods explanatory sequential model. The non-probability sample consisted of 98 university science and engineering students. The study participants had high science self-efficacy, low number of stressors, and were slightly Anglo-oriented bicultural to strongly Anglo-oriented. As expected, the control variables of SAT score and high school GPA were statistically significant predictors of the outcome measures. Together, they accounted for 19.80% of the variation in first year GPA, 13.80% of the variation in earned credit hours, and 11.30% of the variation in intent to remain in the science major. After controlling for SAT scores and high school GPAs, self-efficacy was a statistically significant predictor of credit hours earned and accounted for 5.60% of the variation; its unique contribution in explaining the variation in first year GPA and intent to remain in the science major was not statistically significant. Stress and acculturation were not statistically significant predictors of any of the outcome measures. Analysis of the qualitative data resulted in six themes (a) high science self-efficacy, (b) stressors, (c) positive role of stress, (d) Anglo-oriented, (e) bicultural, and (f) family. The quantitative and qualitative results were synthesized and practical implications were discussed.

Electricity supply efficiency and organizational growth and profitability in Lagos, Nigeria

NASA Astrophysics Data System (ADS)

Adeleke, Adedeji Tajudeen

A modern and efficient infrastructure is a basic necessity for economic development and integration into the global economy. The specific problem was the inadequate and unreliable supply of electricity to manufacturing corporations in Lagos, Nigeria. The purpose of the current quantitative correlational research study was to examine if there was a correlation between electricity supply efficiency and organizational growth and profitability in manufacturing corporations in Lagos, Nigeria. The population of the current correlational research study involved 28 out of 34 manufacturing corporations from various industrial sectors in Lagos, Nigeria, that are listed and traded on the Nigerian Stock Exchange. Spearman rho correlations were used to assess the relationships between independent variables of electricity supply efficiency levels and the dependent variables of organizational growth and profitability. The result of the correlational analysis of the data revealed that there was a statistically significant, strong positive correlation between the Average Gross Income (1998-2007) and Average Actual Electricity supply efficiency level (1998-2007), rho = 0.57; p = 0.002. A statistically significant, strong positive correlation was found between the Average Balance Sheet Size (1998-2007) and Average Actual Electricity Supply Efficiency Level (1998-2007), rho = 0.54; p = 0.003. A statistically significant, strong positive correlation between the Average Profit After Tax (1998-2007) and Average Actual Electricity Supply Efficiency Level (1998-2007), rho = 0.60; p = 0.001, was found. No statistically significant correlation between the Average Return on Investment (1998-2007) and Average Actual Electricity supply efficiency level (1998-2007), rho = 0.19; p = 0.33, was discovered.

Characterizing microstructural features of biomedical samples by statistical analysis of Mueller matrix images

NASA Astrophysics Data System (ADS)

He, Honghui; Dong, Yang; Zhou, Jialing; Ma, Hui

2017-03-01

As one of the salient features of light, polarization contains abundant structural and optical information of media. Recently, as a comprehensive description of polarization property, the Mueller matrix polarimetry has been applied to various biomedical studies such as cancerous tissues detections. In previous works, it has been found that the structural information encoded in the 2D Mueller matrix images can be presented by other transformed parameters with more explicit relationship to certain microstructural features. In this paper, we present a statistical analyzing method to transform the 2D Mueller matrix images into frequency distribution histograms (FDHs) and their central moments to reveal the dominant structural features of samples quantitatively. The experimental results of porcine heart, intestine, stomach, and liver tissues demonstrate that the transformation parameters and central moments based on the statistical analysis of Mueller matrix elements have simple relationships to the dominant microstructural properties of biomedical samples, including the density and orientation of fibrous structures, the depolarization power, diattenuation and absorption abilities. It is shown in this paper that the statistical analysis of 2D images of Mueller matrix elements may provide quantitative or semi-quantitative criteria for biomedical diagnosis.

Quantitative Imaging Biomarkers: A Review of Statistical Methods for Computer Algorithm Comparisons

PubMed Central

2014-01-01

Quantitative biomarkers from medical images are becoming important tools for clinical diagnosis, staging, monitoring, treatment planning, and development of new therapies. While there is a rich history of the development of quantitative imaging biomarker (QIB) techniques, little attention has been paid to the validation and comparison of the computer algorithms that implement the QIB measurements. In this paper we provide a framework for QIB algorithm comparisons. We first review and compare various study designs, including designs with the true value (e.g. phantoms, digital reference images, and zero-change studies), designs with a reference standard (e.g. studies testing equivalence with a reference standard), and designs without a reference standard (e.g. agreement studies and studies of algorithm precision). The statistical methods for comparing QIB algorithms are then presented for various study types using both aggregate and disaggregate approaches. We propose a series of steps for establishing the performance of a QIB algorithm, identify limitations in the current statistical literature, and suggest future directions for research. PMID:24919829

Content-Related Issues Pertaining to Teaching Statistics: Making Decisions about Educational Objectives in Statistics Courses.

ERIC Educational Resources Information Center

Bliss, Leonard B.; Tashakkori, Abbas

This paper discusses the objectives that would be appropriate for statistics classes for students who are not majoring in statistics, evaluation, or quantitative research design. These "non-majors" should be able to choose appropriate analytical methods for specific sets of data based on the research question and the nature of the data, and they…

A Mixed Method Investigation of Social Science Graduate Students' Statistics Anxiety Conditions before and after the Introductory Statistics Course

ERIC Educational Resources Information Center

Huang, Liuli

2018-01-01

Research frequently uses the quantitative approach to explore undergraduate students' anxiety regarding statistics. However, few studies of adults' statistics anxiety use the qualitative method, or a sole focus on graduate students. Moreover, even fewer studies focus on a comparison of adults' anxiety levels before and after an introductory…

Effectiveness of Quantitative Real Time PCR in Long-Term Follow-up of Chronic Myeloid Leukemia Patients.

PubMed

Savasoglu, Kaan; Payzin, Kadriye Bahriye; Ozdemirkiran, Fusun; Berber, Belgin

2015-08-01

To determine the use of the Quantitative Real Time PCR (RQ-PCR) assay follow-up with Chronic Myeloid Leukemia (CML) patients. Cross-sectional observational. Izmir Ataturk Education and Research Hospital, Izmir, Turkey, from 2009 to 2013. Cytogenetic, FISH, RQ-PCR test results from 177 CMLpatients' materials selected between 2009 - 2013 years was set up for comparison analysis. Statistical analysis was performed to compare between FISH, karyotype and RQ-PCR results of the patients. Karyotyping and FISH specificity and sensitivity rates determined by ROC analysis compared with RQ-PCR results. Chi-square test was used to compare test failure rates. Sensitivity and specificity values were determined for karyotyping 17.6 - 98% (p=0.118, p > 0.05) and for FISH 22.5 - 96% (p=0.064, p > 0.05) respectively. FISH sensitivity was slightly higher than karyotyping but there was calculated a strong correlation between them (p < 0.001). RQ-PCR test failure rate did not correlate with other two tests (p > 0.05); however, karyotyping and FISH test failure rate was statistically significant (p < 0.001). Besides, the situation needed for karyotype analysis, RQ-PCR assay can be used alone in the follow-up of CMLdisease.

Identifying sources of fugitive emissions in industrial facilities using trajectory statistical methods

NASA Astrophysics Data System (ADS)

Brereton, Carol A.; Johnson, Matthew R.

2012-05-01

Fugitive pollutant sources from the oil and gas industry are typically quite difficult to find within industrial plants and refineries, yet they are a significant contributor of global greenhouse gas emissions. A novel approach for locating fugitive emission sources using computationally efficient trajectory statistical methods (TSM) has been investigated in detailed proof-of-concept simulations. Four TSMs were examined in a variety of source emissions scenarios developed using transient CFD simulations on the simplified geometry of an actual gas plant: potential source contribution function (PSCF), concentration weighted trajectory (CWT), residence time weighted concentration (RTWC), and quantitative transport bias analysis (QTBA). Quantitative comparisons were made using a correlation measure based on search area from the source(s). PSCF, CWT and RTWC could all distinguish areas near major sources from the surroundings. QTBA successfully located sources in only some cases, even when provided with a large data set. RTWC, given sufficient domain trajectory coverage, distinguished source areas best, but otherwise could produce false source predictions. Using RTWC in conjunction with CWT could overcome this issue as well as reduce sensitivity to noise in the data. The results demonstrate that TSMs are a promising approach for identifying fugitive emissions sources within complex facility geometries.

Job satisfaction of nurses with master of nursing degrees in Poland: quantitative and qualitative analysis.

PubMed

Brayer, Aneta; Marcinowicz, Ludmila

2018-04-03

Understanding the issue of job satisfaction of nurses with master of nursing degrees may help develop organisational changes necessary for better functioning of health care institutions. This study aimed to evaluate the level of job satisfaction among holders of Masters of Nursing degrees employed at health care institutions and to ascertain its determinants. The cross-sectional study was carried out in randomly selected health care institutions in Poland using the Misener Nurse Practitioner Job Satisfaction Survey and an original survey questionnaire with two open-ended questions. Quantitative data were analysed using descriptive and summary statistics. The participants gave highest satisfaction ratings to their relationships with direct superiors and other nurses, as well as their social contacts at work. The lowest ratings were given to the pension scheme and factors connected with remuneration. A highly statistically significant relationship was found between the job classification and the level of professional satisfaction (p < 0.001). Qualitative analysis of responses to the two open-ended questions supported Herzberg's Two-Factor theory: internal factors promoted satisfaction, whilst external ones caused dissatisfaction. Managers of nurses should strengthen the areas that contribute to higher employee satisfaction, particularly interpersonal relationships, by commendation and recognition of work effects.

DSM-5 ASD moves forward into the past.

PubMed

Tsai, Luke Y; Ghaziuddin, Mohammad

2014-02-01

The fifth edition of the diagnostic and statistical manual of mental disorders (DSM-5) (APA in diagnostic and statistical manual of mental disorders, Author, Washington, 2013) has decided to merge the subtypes of pervasive developmental disorders into a single category of autism spectrum disorder (ASD) on the assumption that they cannot be reliably differentiated from one another. The purpose of this review is to analyze the basis of this assumption by examining the comparative studies between Asperger's disorder (AsD) and autistic disorder (AD), and between pervasive developmental disorder not otherwise specified (PDDNOS) and AD. In all, 125 studies compared AsD with AD. Of these, 30 studies concluded that AsD and AD were similar conditions while 95 studies found quantitative and qualitative differences between them. Likewise, 37 studies compared PDDNOS with AD. Nine of these concluded that PDDNOS did not differ significantly from AD while 28 reported quantitative and qualitative differences between them. Taken together, these findings do not support the conceptualization of AD, AsD and PDDNOS as a single category of ASD. Irrespective of the changes proposed by the DSM-5, future research and clinical practice will continue to find ways to meaningfully subtype the ASD.

Cross-Border Healthcare Requests to Publicly Funded Healthcare Insurance: Empirical Analysis.

PubMed

Stewart Ferreira, Lydia

2016-02-01

Despite the legal authority to confirm, override or modify healthcare insurance decisions made by physicians and government officials, health tribunal decisions have not been empirically analyzed. Using a novel quantitative methodology, all 387 Health Services Appeal and Review Board written and publicly available electronic decisions released over a five-year time period were statistically analyzed with respect to Ontario public health insurance requests for global cross-border healthcare. The statistical results found that patients knew their diagnosis prior to requesting cross-border healthcare, and 84% of patients requested specific northern US facilities for specific treatment. Two specific healthcare facilities in the US were requested for either surgery or assessments. A significant number of patients were seeking cross-border healthcare for pain treatment. This research challenges the assumption that cross-border treatment requests result only from domestic delay when instead patients are seeking specific treatments at specific facilities. This novel quantitative research methodology and data source of written and publicly available electronic Health Services Appeal and Review Board decisions should be used to inform policy decision regarding the utilization and evaluation of Canada's healthcare system and publicly funded healthcare insurance. Copyright © 2016 Longwoods Publishing.

Effects of metacognitive instruction on the academic achievement of students in the secondary sciences

NASA Astrophysics Data System (ADS)

Bianchi, Gregory A.

The purpose of this study was to investigate the effects of reflective assessment in the form of situated metacognitive prompts on student achievement in the secondary sciences. A second goal was to determine whether specific gender differences existed in terms of student responsiveness to the metacognitive interventions. Participants in the study consisted of a convenience sample from a population of ninth-grade honors biology students in a large suburban school district located near Seattle, Washington. Beyond answering the specific research questions raised in this study, an additional aim was to broaden the growing body of research pertaining to the effect of metacognition on student achievement. A quasi-experimental, non-equivalent control group design was employed in this study. Descriptive and inferential statistics were computed to address the specific research questions raised. Specifically, a three-way repeated-measures ANOVA was performed. For this purpose, a single within-subjects factor, termed Testing, was defined. Three levels were allocated to this factor, and quantitative data from the Pretest, Posttest, and Retention Test were assigned to the levels, respectively. Group and Gender were defined as between-subjects factors, and both were allocated two levels; the two Group levels were Reflective and Non-Reflective. The effects of Group and Gender on each of the three quantitative measures were examined singly and in interaction with each other. Tests of statistical significance were analyzed at the .05 level. There was a statistically significant effect for Group (Reflective, Non-Reflective) by Testing (Pretest, Posttest, Retention Test). A three-way repeated-measures ANOVA procedure revealed that students in the Reflective group outperformed students in the Non-Reflective group (F = 10.258, p = .002, Partial eta 2 = .088). According to the effect size estimate, almost 9% of variance in the Testing variable was attributable to the Group variable. There was not a significant interaction effect for Gender. A three-way repeated-measures ANOVA procedure revealed that Testing X Group X Gender did not yield a statistically significant F ratio (F = 1.471, p = .228, Partial eta2 = .014). Students in the Reflective group outperformed students in the Non-Reflective group, regardless of gender. The findings of this study offer modest evidence that reflective assessment in the form of situated metacognitive prompts may improve student academic outcomes at the secondary level. This study failed to provide a significant finding regarding gender-related variation in a metacognitive learning cycle.

Reproducibility and Prognosis of Quantitative Features Extracted from CT Images12

PubMed Central

Balagurunathan, Yoganand; Gu, Yuhua; Wang, Hua; Kumar, Virendra; Grove, Olya; Hawkins, Sam; Kim, Jongphil; Goldgof, Dmitry B; Hall, Lawrence O; Gatenby, Robert A; Gillies, Robert J

2014-01-01

We study the reproducibility of quantitative imaging features that are used to describe tumor shape, size, and texture from computed tomography (CT) scans of non-small cell lung cancer (NSCLC). CT images are dependent on various scanning factors. We focus on characterizing image features that are reproducible in the presence of variations due to patient factors and segmentation methods. Thirty-two NSCLC nonenhanced lung CT scans were obtained from the Reference Image Database to Evaluate Response data set. The tumors were segmented using both manual (radiologist expert) and ensemble (software-automated) methods. A set of features (219 three-dimensional and 110 two-dimensional) was computed, and quantitative image features were statistically filtered to identify a subset of reproducible and nonredundant features. The variability in the repeated experiment was measured by the test-retest concordance correlation coefficient (CCCTreT). The natural range in the features, normalized to variance, was measured by the dynamic range (DR). In this study, there were 29 features across segmentation methods found with CCCTreT and DR ≥ 0.9 and R2Bet ≥ 0.95. These reproducible features were tested for predicting radiologist prognostic score; some texture features (run-length and Laws kernels) had an area under the curve of 0.9. The representative features were tested for their prognostic capabilities using an independent NSCLC data set (59 lung adenocarcinomas), where one of the texture features, run-length gray-level nonuniformity, was statistically significant in separating the samples into survival groups (P ≤ .046). PMID:24772210

Quantitative assessment model for gastric cancer screening

PubMed Central

Chen, Kun; Yu, Wei-Ping; Song, Liang; Zhu, Yi-Min

2005-01-01

AIM: To set up a mathematic model for gastric cancer screening and to evaluate its function in mass screening for gastric cancer. METHODS: A case control study was carried on in 66 patients and 198 normal people, then the risk and protective factors of gastric cancer were determined, including heavy manual work, foods such as small yellow-fin tuna, dried small shrimps, squills, crabs, mothers suffering from gastric diseases, spouse alive, use of refrigerators and hot food, etc. According to some principles and methods of probability and fuzzy mathematics, a quantitative assessment model was established as follows: first, we selected some factors significant in statistics, and calculated weight coefficient for each one by two different methods; second, population space was divided into gastric cancer fuzzy subset and non gastric cancer fuzzy subset, then a mathematic model for each subset was established, we got a mathematic expression of attribute degree (AD). RESULTS: Based on the data of 63 patients and 693 normal people, AD of each subject was calculated. Considering the sensitivity and specificity, the thresholds of AD values calculated were configured with 0.20 and 0.17, respectively. According to these thresholds, the sensitivity and specificity of the quantitative model were about 69% and 63%. Moreover, statistical test showed that the identification outcomes of these two different calculation methods were identical (P>0.05). CONCLUSION: The validity of this method is satisfactory. It is convenient, feasible, economic and can be used to determine individual and population risks of gastric cancer. PMID:15655813

Cartilage can be thicker in advanced osteoarthritic knees: a tridimensional quantitative analysis of cartilage thickness at posterior aspect of femoral condyles.

PubMed

Omoumi, Patrick; Babel, Hugo; Jolles, Brigitte M; Favre, Julien

2018-04-16

To test, through tridimensional analysis, whether (1) cartilage thickness at the posterior aspect of femoral condyles differs in knees with medial femorotibial osteoarthritis (OA) compared to non-OA knees; (2) the location of the thickest cartilage at the posterior aspect of femoral condyles differs between OA and non-OA knees. CT arthrograms of knees without radiographic OA (n = 30) and with severe medial femorotibial OA (n = 30) were selected retrospectively from patients over 50 years of age. The groups did not differ in gender, age and femoral size. CT arthrograms were segmented to measure the mean cartilage thickness, the maximal cartilage thickness and its location in a region of interest at the posterior aspect of condyles. For the medial condyle, mean and maximum cartilage thicknesses were statistically significantly higher in OA knees compared to non-OA knees [1.66 vs 1.46 mm (p = 0.03) and 2.56 vs 2.14 mm (p = 0.003), respectively]. The thickest cartilage was located in the half most medial aspect of the posterior medial condyle for both groups, without significant difference between groups. For the lateral condyle, no statistically significant difference between non-OA and OA knees was found (p ≥ 0.17). Cartilage at the posterior aspect of the medial condyle, but not the lateral condyle, is statistically significantly thicker in advanced medial femorotibial OA knees compared to non-OA knees. The thickest cartilage was located in the half most medial aspect of the posterior medial condyle. These results will serve as the basis for future research to determine the histobiological processes involved in this thicker cartilage. Advances in knowledge: This study, through a quantitative tridimensional approach, shows that cartilage at the posterior aspect of the medial condyles is thicker in severe femorotibial osteoarthritic knees compared to non-OA knees. In the posterior aspect of the medial condyle, the thickest cartilage is located in the vicinity of the center of the half most medial aspect of the posterior medial condyle. These results will serve as the basis for future research to determine the histobiological processes involved in this thicker cartilage.

A novel measure and significance testing in data analysis of cell image segmentation.

PubMed

Wu, Jin Chu; Halter, Michael; Kacker, Raghu N; Elliott, John T; Plant, Anne L

2017-03-14

Cell image segmentation (CIS) is an essential part of quantitative imaging of biological cells. Designing a performance measure and conducting significance testing are critical for evaluating and comparing the CIS algorithms for image-based cell assays in cytometry. Many measures and methods have been proposed and implemented to evaluate segmentation methods. However, computing the standard errors (SE) of the measures and their correlation coefficient is not described, and thus the statistical significance of performance differences between CIS algorithms cannot be assessed. We propose the total error rate (TER), a novel performance measure for segmenting all cells in the supervised evaluation. The TER statistically aggregates all misclassification error rates (MER) by taking cell sizes as weights. The MERs are for segmenting each single cell in the population. The TER is fully supported by the pairwise comparisons of MERs using 106 manually segmented ground-truth cells with different sizes and seven CIS algorithms taken from ImageJ. Further, the SE and 95% confidence interval (CI) of TER are computed based on the SE of MER that is calculated using the bootstrap method. An algorithm for computing the correlation coefficient of TERs between two CIS algorithms is also provided. Hence, the 95% CI error bars can be used to classify CIS algorithms. The SEs of TERs and their correlation coefficient can be employed to conduct the hypothesis testing, while the CIs overlap, to determine the statistical significance of the performance differences between CIS algorithms. A novel measure TER of CIS is proposed. The TER's SEs and correlation coefficient are computed. Thereafter, CIS algorithms can be evaluated and compared statistically by conducting the significance testing.

Gender, Math Confidence, and Grit: Relationships with Quantitative Skills and Performance in an Undergraduate Biology Course.

PubMed

Flanagan, K M; Einarson, J

2017-01-01

In a world filled with big data, mathematical models, and statistics, the development of strong quantitative skills is becoming increasingly critical for modern biologists. Teachers in this field must understand how students acquire quantitative skills and explore barriers experienced by students when developing these skills. In this study, we examine the interrelationships among gender, grit, and math confidence for student performance on a pre-post quantitative skills assessment and overall performance in an undergraduate biology course. Here, we show that females significantly underperformed relative to males on a quantitative skills assessment at the start of term. However, females showed significantly higher gains over the semester, such that the gender gap in performance was nearly eliminated by the end of the semester. Math confidence plays an important role in the performance on both the pre and post quantitative skills assessments and overall performance in the course. The effect of grit on student performance, however, is mediated by a student's math confidence; as math confidence increases, the positive effect of grit decreases. Consequently, the positive impact of a student's grittiness is observed most strongly for those students with low math confidence. We also found grit to be positively associated with the midterm score and the final grade in the course. Given the relationships established in this study among gender, grit, and math confidence, we provide "instructor actions" from the literature that can be applied in the classroom to promote the development of quantitative skills in light of our findings. © 2017 K. M. Flanagan and J. Einarson. CBE—Life Sciences Education © 2017 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Quantitative analysis of 18F-NaF dynamic PET/CT cannot differentiate malignant from benign lesions in multiple myeloma

PubMed Central

Sachpekidis, Christos; Hillengass, Jens; Goldschmidt, Hartmut; Anwar, Hoda; Haberkorn, Uwe; Dimitrakopoulou-Strauss, Antonia

2017-01-01

A renewed interest has been recently developed for the highly sensitive bone-seeking radiopharmaceutical 18F-NaF. Aim of the present study is to evaluate the potential utility of quantitative analysis of 18F-NaF dynamic PET/CT data in differentiating malignant from benign degenerative lesions in multiple myeloma (MM). 80 MM patients underwent whole-body PET/CT and dynamic PET/CT scanning of the pelvis with 18F-NaF. PET/CT data evaluation was based on visual (qualitative) assessment, semi-quantitative (SUV) calculations, and absolute quantitative estimations after application of a 2-tissue compartment model and a non-compartmental approach leading to the extraction of fractal dimension (FD). In total 263 MM lesions were demonstrated on 18F-NaF PET/CT. Semi-quantitative and quantitative evaluations were performed for 25 MM lesions as well as for 25 benign, degenerative and traumatic lesions. Mean SUVaverage for MM lesions was 11.9 and mean SUVmax was 23.2. Respectively, SUVaverage and SUVmax for degenerative lesions were 13.5 and 20.2. Kinetic analysis of 18F-NaF revealed the following mean values for MM lesions: K1 = 0.248 (1/min), k3 = 0.359 (1/min), influx (Ki) = 0.107 (1/min), FD = 1.382, while the respective values for degenerative lesions were: K1 = 0.169 (1/min), k3 = 0.422 (1/min), influx (Ki) = 0.095 (1/min), FD = 1. 411. No statistically significant differences between MM and benign degenerative disease regarding SUVaverage, SUVmax, K1, k3 and influx (Ki) were demonstrated. FD was significantly higher in degenerative than in malignant lesions. The present findings show that quantitative analysis of 18F-NaF PET data cannot differentiate malignant from benign degenerative lesions in MM patients, supporting previously published results, which reflect the limited role of 18F-NaF PET/CT in the diagnostic workup of MM. PMID:28913153

Quantitative analysis of sitagliptin using the (19)F-NMR method: a universal technique for fluorinated compound detection.

PubMed

Zhang, Fen-Fen; Jiang, Meng-Hong; Sun, Lin-Lin; Zheng, Feng; Dong, Lei; Shah, Vishva; Shen, Wen-Bin; Ding, Ya

2015-01-07

To expand the application scope of nuclear magnetic resonance (NMR) technology in quantitative analysis of pharmaceutical ingredients, (19)F nuclear magnetic resonance ((19)F-NMR) spectroscopy has been employed as a simple, rapid, and reproducible approach for the detection of a fluorine-containing model drug, sitagliptin phosphate monohydrate (STG). ciprofloxacin (Cipro) has been used as the internal standard (IS). Influential factors, including the relaxation delay time (d1) and pulse angle, impacting the accuracy and precision of spectral data are systematically optimized. Method validation has been carried out in terms of precision and intermediate precision, linearity, limit of detection (LOD) and limit of quantification (LOQ), robustness, and stability. To validate the reliability and feasibility of the (19)F-NMR technology in quantitative analysis of pharmaceutical analytes, the assay result has been compared with that of (1)H-NMR. The statistical F-test and student t-test at 95% confidence level indicate that there is no significant difference between these two methods. Due to the advantages of (19)F-NMR, such as higher resolution and suitability for biological samples, it can be used as a universal technology for the quantitative analysis of other fluorine-containing pharmaceuticals and analytes.

Human papillomavirus infection and the malignant transformation of sinonasal inverted papilloma: A meta-analysis.

PubMed

Zhao, Ren-Wu; Guo, Zhi-Qiang; Zhang, Ru-Xin

2016-06-01

A growing number of molecular epidemiological studies have been conducted to evaluate the association between human papillomavirus (HPV) infection and the malignancy of sinonasal inverted papilloma (SNIP). However, the results remain inconclusive. Here, a meta-analysis was conducted to quantitatively assess this association. Case-control studies investigating SNIP tissues for presence of HPV DNA were identified. The odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by the Mantel-Haenszel method. An assessment of publication bias and sensitivity analysis were also performed. We calculated a pooled OR of 2.16 (95% CI=1.46-3.21, P<0.001) without statistically significant heterogeneity or publication bias. Stratification by HPV type showed a stronger association for patients with high-risk HPV (hrHPV) types, HPV-16, HPV-18, and HPV-16/18 infection (OR=8.8 [95% CI: 4.73-16.38], 8.04 [95% CI: 3.34-19.39], 18.57 [95% CI: 4.56-75.70], and 26.24 [4.35-158.47], respectively). When only using PCR studies, pooled ORs for patients with hrHPV, HPV-16, and HPV18 infection still reached statistical significance. However, Egger's test reflected significant publication bias in the HPV-16 sub-analysis (P=0.06), and the adjusted OR was no longer statistically significant (OR=1.65, 95%CI: 0.58-4.63). These results suggest that HPV infection, especially hrHPV (HPV-18), is significantly associated with malignant SNIP. Copyright © 2016 Elsevier B.V. All rights reserved.

Quantitative imaging biomarkers: a review of statistical methods for technical performance assessment.

PubMed

Raunig, David L; McShane, Lisa M; Pennello, Gene; Gatsonis, Constantine; Carson, Paul L; Voyvodic, James T; Wahl, Richard L; Kurland, Brenda F; Schwarz, Adam J; Gönen, Mithat; Zahlmann, Gudrun; Kondratovich, Marina V; O'Donnell, Kevin; Petrick, Nicholas; Cole, Patricia E; Garra, Brian; Sullivan, Daniel C

2015-02-01

Technological developments and greater rigor in the quantitative measurement of biological features in medical images have given rise to an increased interest in using quantitative imaging biomarkers to measure changes in these features. Critical to the performance of a quantitative imaging biomarker in preclinical or clinical settings are three primary metrology areas of interest: measurement linearity and bias, repeatability, and the ability to consistently reproduce equivalent results when conditions change, as would be expected in any clinical trial. Unfortunately, performance studies to date differ greatly in designs, analysis method, and metrics used to assess a quantitative imaging biomarker for clinical use. It is therefore difficult or not possible to integrate results from different studies or to use reported results to design studies. The Radiological Society of North America and the Quantitative Imaging Biomarker Alliance with technical, radiological, and statistical experts developed a set of technical performance analysis methods, metrics, and study designs that provide terminology, metrics, and methods consistent with widely accepted metrological standards. This document provides a consistent framework for the conduct and evaluation of quantitative imaging biomarker performance studies so that results from multiple studies can be compared, contrasted, or combined. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

[Quantitative analysis of the corneal subbasal nerves in different degrees of dry eye with AutoCAD].

PubMed

Cheng, Y; Wu, J; Zhu, H F; Cheng, Y; Zhu, X P

2016-03-01

To evaluate the practical value of AutoCAD in quantitative analysis of corneal subbasal epithelial nerves with different degrees of dry eye. Ninety patients were divided into groups of mild, moderate, and severe dry eye, 30 patients (60 eyes) in each group. And 30 healthy volunteers were recruited as the normal control group. Confocal microscopy was used to observe the length of the subbasal epithelial nerve plexus. The images were analyzed by AutoCAD software to determine the density (mm/mm(2)), the number of branches, and the curvature score of the subbasal epithelial nerves. These data of patients with dry eye and the controls were statistically compared, by analysis of variance(ANOV). By AutoCAD software, quantitative analysis of the corneal subbasal epithelial nerves was successfully performed. The nerve density in the patients with mild dry eye[(16.70±3.43) mm/mm(2)] was not significantly different from the controls[(15.87 ± 2.75) mm/mm(2)] (P=0.880), but the number of nerval branches 13.43±2.46 and the curvature 3.10±0.80 increased significantly (P<0.001). The nerve density in the patients with moderate and severe dry eye was significantly different from that in the normal control group (F=114.739, P<0.001). The neural density was significantly lower in the patients with severe dry eye than the controls, but there was no significant difference in the curvature scores between the two groups (P= 0.557). AutoCAD software is useful in the quantitative analysis of corneal nerve images under a confocal microscope. The corneal subbasal epithelial nerve density, the number of branches, and the curvature of the nerves are related to the degree of dry eye, and may be used as clinical indicators.

Semi-quantitative proteomics of mammalian cells upon short-term exposure to non-ionizing electromagnetic fields.

PubMed

Kuzniar, Arnold; Laffeber, Charlie; Eppink, Berina; Bezstarosti, Karel; Dekkers, Dick; Woelders, Henri; Zwamborn, A Peter M; Demmers, Jeroen; Lebbink, Joyce H G; Kanaar, Roland

2017-01-01

The potential effects of non-ionizing electromagnetic fields (EMFs), such as those emitted by power-lines (in extremely low frequency range), mobile cellular systems and wireless networking devices (in radio frequency range) on human health have been intensively researched and debated. However, how exposure to these EMFs may lead to biological changes underlying possible health effects is still unclear. To reveal EMF-induced molecular changes, unbiased experiments (without a priori focusing on specific biological processes) with sensitive readouts are required. We present the first proteome-wide semi-quantitative mass spectrometry analysis of human fibroblasts, osteosarcomas and mouse embryonic stem cells exposed to three types of non-ionizing EMFs (ELF 50 Hz, UMTS 2.1 GHz and WiFi 5.8 GHz). We performed controlled in vitro EMF exposures of metabolically labeled mammalian cells followed by reliable statistical analyses of differential protein- and pathway-level regulations using an array of established bioinformatics methods. Our results indicate that less than 1% of the quantitated human or mouse proteome responds to the EMFs by small changes in protein abundance. Further network-based analysis of the differentially regulated proteins did not detect significantly perturbed cellular processes or pathways in human and mouse cells in response to ELF, UMTS or WiFi exposure. In conclusion, our extensive bioinformatics analyses of semi-quantitative mass spectrometry data do not support the notion that the short-time exposures to non-ionizing EMFs have a consistent biologically significant bearing on mammalian cells in culture.

Semi-quantitative proteomics of mammalian cells upon short-term exposure to non-ionizing electromagnetic fields

PubMed Central

Laffeber, Charlie; Eppink, Berina; Bezstarosti, Karel; Dekkers, Dick; Woelders, Henri; Zwamborn, A. Peter M.; Demmers, Jeroen; Lebbink, Joyce H. G.; Kanaar, Roland

2017-01-01

The potential effects of non-ionizing electromagnetic fields (EMFs), such as those emitted by power-lines (in extremely low frequency range), mobile cellular systems and wireless networking devices (in radio frequency range) on human health have been intensively researched and debated. However, how exposure to these EMFs may lead to biological changes underlying possible health effects is still unclear. To reveal EMF-induced molecular changes, unbiased experiments (without a priori focusing on specific biological processes) with sensitive readouts are required. We present the first proteome-wide semi-quantitative mass spectrometry analysis of human fibroblasts, osteosarcomas and mouse embryonic stem cells exposed to three types of non-ionizing EMFs (ELF 50 Hz, UMTS 2.1 GHz and WiFi 5.8 GHz). We performed controlled in vitro EMF exposures of metabolically labeled mammalian cells followed by reliable statistical analyses of differential protein- and pathway-level regulations using an array of established bioinformatics methods. Our results indicate that less than 1% of the quantitated human or mouse proteome responds to the EMFs by small changes in protein abundance. Further network-based analysis of the differentially regulated proteins did not detect significantly perturbed cellular processes or pathways in human and mouse cells in response to ELF, UMTS or WiFi exposure. In conclusion, our extensive bioinformatics analyses of semi-quantitative mass spectrometry data do not support the notion that the short-time exposures to non-ionizing EMFs have a consistent biologically significant bearing on mammalian cells in culture. PMID:28234898

Phenotypic characterization of glioblastoma identified through shape descriptors

NASA Astrophysics Data System (ADS)

Chaddad, Ahmad; Desrosiers, Christian; Toews, Matthew

2016-03-01

This paper proposes quantitatively describing the shape of glioblastoma (GBM) tissue phenotypes as a set of shape features derived from segmentations, for the purposes of discriminating between GBM phenotypes and monitoring tumor progression. GBM patients were identified from the Cancer Genome Atlas, and quantitative MR imaging data were obtained from the Cancer Imaging Archive. Three GBM tissue phenotypes are considered including necrosis, active tumor and edema/invasion. Volumetric tissue segmentations are obtained from registered T1˗weighted (T1˗WI) postcontrast and fluid-attenuated inversion recovery (FLAIR) MRI modalities. Shape features are computed from respective tissue phenotype segmentations, and a Kruskal-Wallis test was employed to select features capable of classification with a significance level of p < 0.05. Several classifier models are employed to distinguish phenotypes, where a leave-one-out cross-validation was performed. Eight features were found statistically significant for classifying GBM phenotypes with p <0.05, orientation is uninformative. Quantitative evaluations show the SVM results in the highest classification accuracy of 87.50%, sensitivity of 94.59% and specificity of 92.77%. In summary, the shape descriptors proposed in this work show high performance in predicting GBM tissue phenotypes. They are thus closely linked to morphological characteristics of GBM phenotypes and could potentially be used in a computer assisted labeling system.

Identification of expression quantitative trait loci by the interaction analysis using genetic algorithm.

PubMed

Namkung, Junghyun; Nam, Jin-Wu; Park, Taesung

2007-01-01

Many genes with major effects on quantitative traits have been reported to interact with other genes. However, finding a group of interacting genes from thousands of SNPs is challenging. Hence, an efficient and robust algorithm is needed. The genetic algorithm (GA) is useful in searching for the optimal solution from a very large searchable space. In this study, we show that genome-wide interaction analysis using GA and a statistical interaction model can provide a practical method to detect biologically interacting loci. We focus our search on transcriptional regulators by analyzing gene x gene interactions for cancer-related genes. The expression values of three cancer-related genes were selected from the expression data of the Genetic Analysis Workshop 15 Problem 1 data set. We implemented a GA to identify the expression quantitative trait loci that are significantly associated with expression levels of the cancer-related genes. The time complexity of the GA was compared with that of an exhaustive search algorithm. As a result, our GA, which included heuristic methods, such as archive, elitism, and local search, has greatly reduced computational time in a genome-wide search for gene x gene interactions. In general, the GA took one-fifth the computation time of an exhaustive search for the most significant pair of single-nucleotide polymorphisms.

Identification of expression quantitative trait loci by the interaction analysis using genetic algorithm

PubMed Central

Namkung, Junghyun; Nam, Jin-Wu; Park, Taesung

2007-01-01

Many genes with major effects on quantitative traits have been reported to interact with other genes. However, finding a group of interacting genes from thousands of SNPs is challenging. Hence, an efficient and robust algorithm is needed. The genetic algorithm (GA) is useful in searching for the optimal solution from a very large searchable space. In this study, we show that genome-wide interaction analysis using GA and a statistical interaction model can provide a practical method to detect biologically interacting loci. We focus our search on transcriptional regulators by analyzing gene × gene interactions for cancer-related genes. The expression values of three cancer-related genes were selected from the expression data of the Genetic Analysis Workshop 15 Problem 1 data set. We implemented a GA to identify the expression quantitative trait loci that are significantly associated with expression levels of the cancer-related genes. The time complexity of the GA was compared with that of an exhaustive search algorithm. As a result, our GA, which included heuristic methods, such as archive, elitism, and local search, has greatly reduced computational time in a genome-wide search for gene × gene interactions. In general, the GA took one-fifth the computation time of an exhaustive search for the most significant pair of single-nucleotide polymorphisms. PMID:18466570

Quantitative contrast-enhanced ultrasound for monitoring vedolizumab therapy in inflammatory bowel disease patients: a pilot study.

PubMed

Goertz, Ruediger S; Klett, Daniel; Wildner, Dane; Atreya, Raja; Neurath, Markus F; Strobel, Deike

2018-01-01

Background Microvascularization of the bowel wall can be visualized and quantified non-invasively by software-assisted analysis of derived time-intensity curves. Purpose To perform software-based quantification of bowel wall perfusion using quantitative contrast-enhanced ultrasound (CEUS) according to clinical response in patients with inflammatory bowel disease treated with vedolizumab. Material and Methods In a prospective study, in 18 out of 34 patients, high-frequency ultrasound of bowel wall thickness using color Doppler flow combined with CEUS was performed at baseline and after 14 weeks of treatment with vedolizumab. Clinical activity scores at week 14 were used to differentiate between responders and non-responders. CEUS parameters were calculated by software analysis of the video loops. Results Nine of 18 patients (11 with Crohn's disease and seven with ulcerative colitis) showed response to treatment with vedolizumab. Overall, the responder group showed a significant decrease in the semi-quantitative color Doppler vascularization score. Amplitude-derived CEUS parameters of mural microvascularization such as peak enhancement or wash-in rate decreased in responders, in contrast with non-responders. Time-derived parameters remained stable or increased during treatment in all patients. Conclusion Analysis of bowel microvascularization by CEUS shows statistically significant changes in the wash-in-rate related to response of vedolizumab therapy.

Statistical correction of the Winner’s Curse explains replication variability in quantitative trait genome-wide association studies

PubMed Central

Pe’er, Itsik

2017-01-01

Genome-wide association studies (GWAS) have identified hundreds of SNPs responsible for variation in human quantitative traits. However, genome-wide-significant associations often fail to replicate across independent cohorts, in apparent inconsistency with their apparent strong effects in discovery cohorts. This limited success of replication raises pervasive questions about the utility of the GWAS field. We identify all 332 studies of quantitative traits from the NHGRI-EBI GWAS Database with attempted replication. We find that the majority of studies provide insufficient data to evaluate replication rates. The remaining papers replicate significantly worse than expected (p < 10−14), even when adjusting for regression-to-the-mean of effect size between discovery- and replication-cohorts termed the Winner’s Curse (p < 10−16). We show this is due in part to misreporting replication cohort-size as a maximum number, rather than per-locus one. In 39 studies accurately reporting per-locus cohort-size for attempted replication of 707 loci in samples with similar ancestry, replication rate matched expectation (predicted 458, observed 457, p = 0.94). In contrast, ancestry differences between replication and discovery (13 studies, 385 loci) cause the most highly-powered decile of loci to replicate worse than expected, due to difference in linkage disequilibrium. PMID:28715421

Preserved pontine glucose metabolism in Alzheimer disease: A reference region for functional brain image (PET) analysis

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

Minoshima, Satoshi; Frey, K.A.; Foster, N.L.

1995-07-01

Our goal was to examine regional preservation of energy metabolism in Alzheimer disease (AD) and to evaluate effects of PET data normalization to reference regions. Regional metabolic rates in the pons, thalamus, putamen, sensorimotor cortex, visual cortex, and cerebellum (reference regions) were determined stereotaxically and examined in 37 patients with probable AD and 22 normal controls based on quantitative {sup 18}FDG-PET measurements. Following normalization of metabolic rates of the parietotemporal association cortex and whole brain to each reference region, distinctions of the two groups were assessed. The pons showed the best preservation of glucose metabolism in AD. Other reference regionsmore » showed relatively preserved metabolism compared with the parietotemporal association cortex and whole brain, but had significant metabolic reduction. Data normalization to the pons not only enhanced statistical significance of metabolic reduction in the parietotemporal association cortex, but also preserved the presence of global cerebral metabolic reduction indicated in analysis of the quantitative data. Energy metabolism in the pons in probable AD is well preserved. The pons is a reliable reference for data normalization and will enhance diagnostic accuracy and efficiency of quantitative and nonquantitative functional brain imaging. 39 refs., 2 figs., 3 tabs.« less

Quantitative trait loci for a neurocranium deformity, lack of operculum, in gilthead seabream (Sparus aurata L.).

PubMed

Negrín-Báez, D; Navarro, A; Afonso, J M; Toro, M A; Zamorano, M J

2016-04-01

Lack of operculum, a neurocranial deformity, is the most common external abnormality to be found among industrially produced gilthead seabream (Sparus aurata L.), and this entails significant financial losses. This study conducts, for the first time in this species, a quantitative trait loci (QTL) analysis of the lack of operculum. A total of 142 individuals from a paternal half-sibling family (six full-sibling families) were selected for QTL mapping. They had previously shown a highly significant association with the prevalence of lack of operculum in a segregation analysis. All the fish were genotyped for 106 microsatellite markers using a set of multiplex PCRs (ReMsa1-ReMsa13). A linear regression methodology was used for the QTL analysis. Four QTL were detected for this deformity, two of which (QTLOP1 and QTLOP2) were significant. They were located at LG (linkage group) nine and LG10 respectively. Both QTL showed a large effect (about 27%), and furthermore, the association between lack of operculum and sire allelic segregation observed was statistically significant in the QTLOP1 analysis. These results represent a significant step towards including marker-assisted selection for this deformity in genetic breeding programmes to reduce the incidence of the deformity in the species. © 2016 Stichting International Foundation for Animal Genetics.

Quantitative Myocardial Perfusion Imaging Versus Visual Analysis in Diagnosing Myocardial Ischemia: A CE-MARC Substudy.

PubMed

Biglands, John D; Ibraheem, Montasir; Magee, Derek R; Radjenovic, Aleksandra; Plein, Sven; Greenwood, John P

2018-05-01

This study sought to compare the diagnostic accuracy of visual and quantitative analyses of myocardial perfusion cardiovascular magnetic resonance against a reference standard of quantitative coronary angiography. Visual analysis of perfusion cardiovascular magnetic resonance studies for assessing myocardial perfusion has been shown to have high diagnostic accuracy for coronary artery disease. However, only a few small studies have assessed the diagnostic accuracy of quantitative myocardial perfusion. This retrospective study included 128 patients randomly selected from the CE-MARC (Clinical Evaluation of Magnetic Resonance Imaging in Coronary Heart Disease) study population such that the distribution of risk factors and disease status was proportionate to the full population. Visual analysis results of cardiovascular magnetic resonance perfusion images, by consensus of 2 expert readers, were taken from the original study reports. Quantitative myocardial blood flow estimates were obtained using Fermi-constrained deconvolution. The reference standard for myocardial ischemia was a quantitative coronary x-ray angiogram stenosis severity of ≥70% diameter in any coronary artery of >2 mm diameter, or ≥50% in the left main stem. Diagnostic performance was calculated using receiver-operating characteristic curve analysis. The area under the curve for visual analysis was 0.88 (95% confidence interval: 0.81 to 0.95) with a sensitivity of 81.0% (95% confidence interval: 69.1% to 92.8%) and specificity of 86.0% (95% confidence interval: 78.7% to 93.4%). For quantitative stress myocardial blood flow the area under the curve was 0.89 (95% confidence interval: 0.83 to 0.96) with a sensitivity of 87.5% (95% confidence interval: 77.3% to 97.7%) and specificity of 84.5% (95% confidence interval: 76.8% to 92.3%). There was no statistically significant difference between the diagnostic performance of quantitative and visual analyses (p = 0.72). Incorporating rest myocardial blood flow values to generate a myocardial perfusion reserve did not significantly increase the quantitative analysis area under the curve (p = 0.79). Quantitative perfusion has a high diagnostic accuracy for detecting coronary artery disease but is not superior to visual analysis. The incorporation of rest perfusion imaging does not improve diagnostic accuracy in quantitative perfusion analysis. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Potential Values of Incorporating a Multiple-Choice Question Construction in Physics Experimentation Instruction

NASA Astrophysics Data System (ADS)

Yu, Fu-Yun; Liu, Yu-Hsin

2005-09-01

The potential value of a multiple-choice question-construction instructional strategy for the support of students’ learning of physics experiments was examined in the study. Forty-two university freshmen participated in the study for a whole semester. A constant comparison method adopted to categorize students’ qualitative data indicated that the influences of multiple-choice question construction were evident in several significant ways (promoting constructive and productive studying habits; reflecting and previewing course-related materials; increasing in-group communication and interaction; breaking passive learning style and habits, etc.), which, worked together, not only enhanced students’ comprehension and retention of the obtained knowledge, but also helped distil a sense of empowerment and learning community within the participants. Analysis with one-group t-tests, using 3 as the expected mean, on quantitative data further found that students’ satisfaction toward past learning experience, and perceptions toward this strategy’s potentials for promoting learning were statistically significant at the 0.0005 level, while learning anxiety was not statistically significant. Suggestions for incorporating question-generation activities within classroom and topics for future studies were rendered.

Critical Analysis of Primary Literature in a Master’s-Level Class: Effects on Self-Efficacy and Science-Process Skills

PubMed Central

Abdullah, Christopher; Parris, Julian; Lie, Richard; Guzdar, Amy; Tour, Ella

2015-01-01

The ability to think analytically and creatively is crucial for success in the modern workforce, particularly for graduate students, who often aim to become physicians or researchers. Analysis of the primary literature provides an excellent opportunity to practice these skills. We describe a course that includes a structured analysis of four research papers from diverse fields of biology and group exercises in proposing experiments that would follow up on these papers. To facilitate a critical approach to primary literature, we included a paper with questionable data interpretation and two papers investigating the same biological question yet reaching opposite conclusions. We report a significant increase in students’ self-efficacy in analyzing data from research papers, evaluating authors’ conclusions, and designing experiments. Using our science-process skills test, we observe a statistically significant increase in students’ ability to propose an experiment that matches the goal of investigation. We also detect gains in interpretation of controls and quantitative analysis of data. No statistically significant changes were observed in questions that tested the skills of interpretation, inference, and evaluation. PMID:26250564

Efficiency Analysis: Enhancing the Statistical and Evaluative Power of the Regression-Discontinuity Design.

ERIC Educational Resources Information Center

Madhere, Serge

An analytic procedure, efficiency analysis, is proposed for improving the utility of quantitative program evaluation for decision making. The three features of the procedure are explained: (1) for statistical control, it adopts and extends the regression-discontinuity design; (2) for statistical inferences, it de-emphasizes hypothesis testing in…

On a Calculus-Based Statistics Course for Life Science Students

ERIC Educational Resources Information Center

Watkins, Joseph C.

2010-01-01

The choice of pedagogy in statistics should take advantage of the quantitative capabilities and scientific background of the students. In this article, we propose a model for a statistics course that assumes student competency in calculus and a broadening knowledge in biology. We illustrate our methods and practices through examples from the…

Thinking Statistically in Writing: Journals and Discussion Boards in an Introductory Statistics Course

ERIC Educational Resources Information Center

Theoret, Julie M.; Luna, Andrea

2009-01-01

This action research combined qualitative and quantitative techniques to investigate two different types of writing assignments in an introductory undergraduate statistics course. The assignments were written in response to the same set of prompts but in two different ways: homework journal assignments or initial posts to a computer discussion…

Teaching Biology through Statistics: Application of Statistical Methods in Genetics and Zoology Courses

PubMed Central

Colon-Berlingeri, Migdalisel; Burrowes, Patricia A.

2011-01-01

Incorporation of mathematics into biology curricula is critical to underscore for undergraduate students the relevance of mathematics to most fields of biology and the usefulness of developing quantitative process skills demanded in modern biology. At our institution, we have made significant changes to better integrate mathematics into the undergraduate biology curriculum. The curricular revision included changes in the suggested course sequence, addition of statistics and precalculus as prerequisites to core science courses, and incorporating interdisciplinary (math–biology) learning activities in genetics and zoology courses. In this article, we describe the activities developed for these two courses and the assessment tools used to measure the learning that took place with respect to biology and statistics. We distinguished the effectiveness of these learning opportunities in helping students improve their understanding of the math and statistical concepts addressed and, more importantly, their ability to apply them to solve a biological problem. We also identified areas that need emphasis in both biology and mathematics courses. In light of our observations, we recommend best practices that biology and mathematics academic departments can implement to train undergraduates for the demands of modern biology. PMID:21885822

Recovering incomplete data using Statistical Multiple Imputations (SMI): a case study in environmental chemistry.

PubMed

Mercer, Theresa G; Frostick, Lynne E; Walmsley, Anthony D

2011-10-15

This paper presents a statistical technique that can be applied to environmental chemistry data where missing values and limit of detection levels prevent the application of statistics. A working example is taken from an environmental leaching study that was set up to determine if there were significant differences in levels of leached arsenic (As), chromium (Cr) and copper (Cu) between lysimeters containing preservative treated wood waste and those containing untreated wood. Fourteen lysimeters were setup and left in natural conditions for 21 weeks. The resultant leachate was analysed by ICP-OES to determine the As, Cr and Cu concentrations. However, due to the variation inherent in each lysimeter combined with the limits of detection offered by ICP-OES, the collected quantitative data was somewhat incomplete. Initial data analysis was hampered by the number of 'missing values' in the data. To recover the dataset, the statistical tool of Statistical Multiple Imputation (SMI) was applied, and the data was re-analysed successfully. It was demonstrated that using SMI did not affect the variance in the data, but facilitated analysis of the complete dataset. Copyright © 2011 Elsevier B.V. All rights reserved.

Teaching biology through statistics: application of statistical methods in genetics and zoology courses.

PubMed

Colon-Berlingeri, Migdalisel; Burrowes, Patricia A

2011-01-01

Incorporation of mathematics into biology curricula is critical to underscore for undergraduate students the relevance of mathematics to most fields of biology and the usefulness of developing quantitative process skills demanded in modern biology. At our institution, we have made significant changes to better integrate mathematics into the undergraduate biology curriculum. The curricular revision included changes in the suggested course sequence, addition of statistics and precalculus as prerequisites to core science courses, and incorporating interdisciplinary (math-biology) learning activities in genetics and zoology courses. In this article, we describe the activities developed for these two courses and the assessment tools used to measure the learning that took place with respect to biology and statistics. We distinguished the effectiveness of these learning opportunities in helping students improve their understanding of the math and statistical concepts addressed and, more importantly, their ability to apply them to solve a biological problem. We also identified areas that need emphasis in both biology and mathematics courses. In light of our observations, we recommend best practices that biology and mathematics academic departments can implement to train undergraduates for the demands of modern biology.

Quantifying Safety Margin Using the Risk-Informed Safety Margin Characterization (RISMC)

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

Grabaskas, David; Bucknor, Matthew; Brunett, Acacia

2015-04-26

The Risk-Informed Safety Margin Characterization (RISMC), developed by Idaho National Laboratory as part of the Light-Water Reactor Sustainability Project, utilizes a probabilistic safety margin comparison between a load and capacity distribution, rather than a deterministic comparison between two values, as is usually done in best-estimate plus uncertainty analyses. The goal is to determine the failure probability, or in other words, the probability of the system load equaling or exceeding the system capacity. While this method has been used in pilot studies, there has been little work conducted investigating the statistical significance of the resulting failure probability. In particular, it ismore » difficult to determine how many simulations are necessary to properly characterize the failure probability. This work uses classical (frequentist) statistics and confidence intervals to examine the impact in statistical accuracy when the number of simulations is varied. Two methods are proposed to establish confidence intervals related to the failure probability established using a RISMC analysis. The confidence interval provides information about the statistical accuracy of the method utilized to explore the uncertainty space, and offers a quantitative method to gauge the increase in statistical accuracy due to performing additional simulations.« less

A heuristic statistical stopping rule for iterative reconstruction in emission tomography.

PubMed

Ben Bouallègue, F; Crouzet, J F; Mariano-Goulart, D

2013-01-01

We propose a statistical stopping criterion for iterative reconstruction in emission tomography based on a heuristic statistical description of the reconstruction process. The method was assessed for MLEM reconstruction. Based on Monte-Carlo numerical simulations and using a perfectly modeled system matrix, our method was compared with classical iterative reconstruction followed by low-pass filtering in terms of Euclidian distance to the exact object, noise, and resolution. The stopping criterion was then evaluated with realistic PET data of a Hoffman brain phantom produced using the GATE platform for different count levels. The numerical experiments showed that compared with the classical method, our technique yielded significant improvement of the noise-resolution tradeoff for a wide range of counting statistics compatible with routine clinical settings. When working with realistic data, the stopping rule allowed a qualitatively and quantitatively efficient determination of the optimal image. Our method appears to give a reliable estimation of the optimal stopping point for iterative reconstruction. It should thus be of practical interest as it produces images with similar or better quality than classical post-filtered iterative reconstruction with a mastered computation time.

A Dimensionally Reduced Clustering Methodology for Heterogeneous Occupational Medicine Data Mining.

PubMed

Saâdaoui, Foued; Bertrand, Pierre R; Boudet, Gil; Rouffiac, Karine; Dutheil, Frédéric; Chamoux, Alain

2015-10-01

Clustering is a set of techniques of the statistical learning aimed at finding structures of heterogeneous partitions grouping homogenous data called clusters. There are several fields in which clustering was successfully applied, such as medicine, biology, finance, economics, etc. In this paper, we introduce the notion of clustering in multifactorial data analysis problems. A case study is conducted for an occupational medicine problem with the purpose of analyzing patterns in a population of 813 individuals. To reduce the data set dimensionality, we base our approach on the Principal Component Analysis (PCA), which is the statistical tool most commonly used in factorial analysis. However, the problems in nature, especially in medicine, are often based on heterogeneous-type qualitative-quantitative measurements, whereas PCA only processes quantitative ones. Besides, qualitative data are originally unobservable quantitative responses that are usually binary-coded. Hence, we propose a new set of strategies allowing to simultaneously handle quantitative and qualitative data. The principle of this approach is to perform a projection of the qualitative variables on the subspaces spanned by quantitative ones. Subsequently, an optimal model is allocated to the resulting PCA-regressed subspaces.

DAnTE: a statistical tool for quantitative analysis of –omics data

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

Polpitiya, Ashoka D.; Qian, Weijun; Jaitly, Navdeep

2008-05-03

DAnTE (Data Analysis Tool Extension) is a statistical tool designed to address challenges unique to quantitative bottom-up, shotgun proteomics data. This tool has also been demonstrated for microarray data and can easily be extended to other high-throughput data types. DAnTE features selected normalization methods, missing value imputation algorithms, peptide to protein rollup methods, an extensive array of plotting functions, and a comprehensive ANOVA scheme that can handle unbalanced data and random effects. The Graphical User Interface (GUI) is designed to be very intuitive and user friendly.

Compensatory Shift of Subcallosal Area and Paraterminal Gyrus White Matter Parameters on DTI in Patients with Alzheimer Disease.

PubMed

Kuchtova, Barbora; Wurst, Zdenek; Mrzilkova, Jana; Ibrahim, Ibrahim; Tintera, Jaroslav; Bartos, Ales; Musil, Vladimir; Kieslich, Karel; Zach, Petr

2018-01-01

Alzheimer disease is traditionally conceptualized as a disease of brain gray matter, however, studies with diffusion tensor imaging have demonstrated that Alzheimer disease also involves alterations in white matter integrity. We measured number of tracts, tracts length, tract volume, quantitative anisotropy and general fractional anisotropy of neuronal tracts in subcallosal area, paraterminal gyrus and fornix in patients with Alzheimer disease and healthy age-matched controls. Our hypothesis was that patients with Alzheimer disease should exhibit decrease in the integrity of these white matter structures that are crucial for semantic memory function. For our study were selected 24 patients with confirmed Alzheimer disease diagnosis and 24 healthy controls (AD center, Department of Neurology, Charles University, Prague, Czech Republic). Statistically significant differences between the patients with Alzheimer disease and the control group were found both on the left and right fornices but only concerning the tract numbers and tract length. The subcallosal area and paraterminal gyrus showed statistically significant differences between the patients with Alzheimer disease and the control group, but only on the left side and only associated with the tract volume and quantitative anisotropy. Our explanation for these findings lies in the severe hippocampal atrophy (and subsequent loss of function) with compensatory hypertrophy of the subcallosal area and paraterminal gyrus neuronal fibers that occurs in Alzheimer's disease, as an adaptation to the loss of projection from the hippocampal formation via fornix. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Analysis of the quantitative dermatoglyphics of the digito-palmar complex in patients with multiple sclerosis.

PubMed

Supe, S; Milicić, J; Pavićević, R

1997-06-01

Recent studies on the etiopathogenesis of multiple sclerosis (MS) all point out that there is a polygenetical predisposition for this illness. The so called "MS Trait" determines the reactivity of the immunological system upon ecological factors. The development of the glyphological science and the study of the characteristics of the digito-palmar dermatoglyphic complex (for which it was established that they are polygenetically determined characteristics) all enable a better insight into the genetic development during early embriogenesis. The aim of this study was to estimate certain differences in the dermatoglyphics of digito-palmar complexes between the group with multiple sclerosis and the comparable, phenotypically healthy groups of both sexes. This study is based on the analysis of 18 quantitative characteristics of the digito-palmar complex in 125 patients with multiple sclerosis (41 males and 84 females) in comparison to a group of 400 phenotypically healthy patients (200 males and 200 females). The conducted analysis pointed towards a statistically significant decrease of the number of digital and palmar ridges, as well as with lower values of atd angles in a group of MS patients of both sexes. The main discriminators were the characteristic palmar dermatoglyphics with the possibility that the discriminate analysis classifies over 80% of the examinees which exceeds the statistical significance. The results of this study suggest a possible discrimination of patients with MS and the phenotypically health population through the analysis of the dermatoglyphic status, and therefore the possibility that multiple sclerosis is genetically predisposed disease.

Improving Evaluation of Dental Hygiene Students' Cultural Competence with a Mixed-Methods Approach.

PubMed

Flynn, Priscilla; Sarkarati, Nassim

2018-02-01

Most dental hygiene educational programs include cultural competence education, but may not evaluate student outcomes. The aim of this study was to design and implement a mixed-methods evaluation to measure dental hygiene students' progression toward cultural competence. Two cohorts consisting of consecutive classes in one U.S. dental hygiene program participated in the study. A total of 47 dental hygiene students (100% response rate) completed self-assessments to measure their attitudes and knowledge at three time points between 2014 and 2016. Mean scores were calculated for three domains: Physical Environment, Communication, and Values. Qualitative analysis of the students' cultural diversity papers was also conducted to further evaluate students' knowledge and skills. Bennett's five-level conceptual framework was used to code phrases or sentences to place students in the general categories of ethnocentric or ethno-relative. The quantitative and qualitative results yielded different outcomes for Cohort 1, but not for Cohort 2. The Cohort 1 students assessed themselves statistically significantly lower over time in one of the three measured domains. However, the Cohort 2 students assessed themselves as statistically significantly more culturally competent in all three domains. Qualitative results placed 72% of Cohort 1 students and 83% of Cohort 2 students in the more desirable ethno-relative category. Since quantitative methods consisting of student self-assessments may not adequately measure students' cultural competence, adding qualitative methods to measure skills specific to patient care in this study added a robust dimension to evaluating this complex dental hygiene student competence.

Quantitative topographic differentiation of the neonatal EEG.

PubMed

Paul, Karel; Krajca, Vladimír; Roth, Zdenek; Melichar, Jan; Petránek, Svojmil

2006-09-01

To test the discriminatory topographic potential of a new method of the automatic EEG analysis in neonates. A quantitative description of the neonatal EEG can contribute to the objective assessment of the functional state of the brain, and may improve the precision of diagnosing cerebral dysfunctions manifested by 'disorganization', 'dysrhythmia' or 'dysmaturity'. 21 healthy, full-term newborns were examined polygraphically during sleep (EEG-8 referential derivations, respiration, ECG, EOG, EMG). From each EEG record, two 5-min samples (one from the middle of quiet sleep, the other from the middle of active sleep) were subject to subsequent automatic analysis and were described by 13 variables: spectral features and features describing shape and variability of the signal. The data from individual infants were averaged and the number of variables was reduced by factor analysis. All factors identified by factor analysis were statistically significantly influenced by the location of derivation. A large number of statistically significant differences were also established when comparing the effects of individual derivations on each of the 13 measured variables. Both spectral features and features describing shape and variability of the signal are largely accountable for the topographic differentiation of the neonatal EEG. The presented method of the automatic EEG analysis is capable to assess the topographic characteristics of the neonatal EEG, and it is adequately sensitive and describes the neonatal electroencephalogram with sufficient precision. The discriminatory capability of the used method represents a promise for their application in the clinical practice.

Kinetics of N-Glycan Release from Human Immunoglobulin G (IgG) by PNGase F: All Glycans Are Not Created Equal.

PubMed

Huang, Yining; Orlando, Ron

2017-12-01

The biologic activity of IgG molecules is modulated by its crystallizable fragment N-glycosylation, and thus, the analysis of IgG glycosylation is critical. A standard approach to analyze glycosylation of IgGs involves the release of the N-glycans by the enzyme peptide N-glycosidase F, which cleaves the linkage between the asparagine residue and innermost N-acetylglucosamine (GlcNAc) of all N-glycans except those containing a 3-linked fucose attached to the reducing terminal GlcNAc residue. The importance of obtaining complete glycan release for accurate quantitation led us to investigate the kinetics of this de-glycosylation reaction for IgG glycopeptides and to determine the effect of glycan structure and amino acid sequence on the rate of glycan release from glycopeptides of IgGs. This study revealed that the slight differences in amino acid sequences did not lead to a statistically different deglycosylation rate. However, statistically significant differences in the deglycosylation rate constants were observed between glycopeptides differing only in glycan structure ( i.e. , nonfucosylated, fucosylated, bisecting-GlcNAc, sialylated, etc .). For example, a single sialic acid residue was found to decrease the rate by a factor of 3. Similar reductions in rate were associated with the presence of a bisecting-GlcNAc. We predict the differences in release kinetics can lead to significant quantitative variations of the glycosylation study of IgGs.

Quantitative sensory testing of temperature, pain, and touch in adults with Down syndrome.

PubMed

de Knegt, Nanda; Defrin, Ruth; Schuengel, Carlo; Lobbezoo, Frank; Evenhuis, Heleen; Scherder, Erik

2015-12-01

The spinothalamic pathway mediates sensations of temperature, pain, and touch. These functions seem impaired in children with Down syndrome (DS), but have not been extensively examined in adults. The objective of the present study was to compare the spinothalamic-mediated sensory functions between adults with DS and adults from the general population and to examine in the DS group the relationship between the sensory functions and level of intellectual functioning. Quantitative sensory testing (QST) was performed in 188 adults with DS (mean age 37.5 years) and 142 age-matched control participants (median age 40.5 years). Temperature, pain, and touch were evaluated with tests for cold-warm discrimination, sharp-dull discrimination (pinprick), and tactile threshold, respectively. Level of intellectual functioning was estimated with the Social Functioning Scale for Intellectual Disability (intellectual disability level) and the Wechsler Preschool and Primary Scale of Intelligence--Revised (intelligence level). Overall, the difference in spinothalamic-mediated sensory functions between the DS and control groups was not statistically significant. However, DS participants with a lower intelligence level had a statistically significant lower performance on the sharp-dull discrimination test than DS participants with higher intelligence level (adjusted p=.006) and control participants (adjusted p=.017). It was concluded that intellectual functioning level is an important factor to take into account for the assessment of spinothalamic-mediated sensory functioning in adults with DS: a lower level could coincide with impaired sensory functioning, but could also hamper QST assessment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparison of 18F-FDG PET/CT and PET/MRI in patients with multiple myeloma

PubMed Central

Sachpekidis, Christos; Hillengass, Jens; Goldschmidt, Hartmut; Mosebach, Jennifer; Pan, Leyun; Schlemmer, Heinz-Peter; Haberkorn, Uwe; Dimitrakopoulou-Strauss, Antonia

2015-01-01

PET/MRI represents a promising hybrid imaging modality with several potential clinical applications. Although PET/MRI seems highly attractive in the diagnostic approach of multiple myeloma (MM), its role has not yet been evaluated. The aims of this prospective study are to evaluate the feasibility of 18F-FDG PET/MRI in detection of MM lesions, and to investigate the reproducibility of bone marrow lesions detection and quantitative data of 18F-FDG uptake between the functional (PET) component of PET/CT and PET/MRI in MM patients. The study includes 30 MM patients. All patients initially underwent 18F-FDG PET/CT (60 min p.i.), followed by PET/MRI (120 min p.i.). PET/CT and PET/MRI data were assessed and compared based on qualitative (lesion detection) and quantitative (SUV) evaluation. The hybrid PET/MRI system provided good image quality in all cases without artefacts. PET/MRI identified 65 of the 69 lesions, which were detectable with PET/CT (94.2%). Quantitative PET evaluations showed the following mean values in MM lesions: SUVaverage=5.5 and SUVmax=7.9 for PET/CT; SUVaverage=3.9 and SUVmax=5.8 for PET/MRI. Both SUVaverage and SUVmax were significantly higher on PET/CT than on PET/MRI. Spearman correlation analysis demonstrated a strong correlation between both lesional SUVaverage (r=0.744) and lesional SUVmax (r=0.855) values derived from PET/CT and PET/MRI. Regarding detection of myeloma skeletal lesions, PET/MRI exhibited equivalent performance to PET/CT. In terms of tracer uptake quantitation, a significant correlation between the two techniques was demonstrated, despite the statistically significant differences in lesional SUVs between PET/CT and PET/MRI. PMID:26550538

Depth-Dependent Glycosaminoglycan Concentration in Articular Cartilage by Quantitative Contrast-Enhanced Micro–Computed Tomography

PubMed Central

Mittelstaedt, Daniel

2015-01-01

Objective A quantitative contrast-enhanced micro–computed tomography (qCECT) method was developed to investigate the depth dependency and heterogeneity of the glycosaminoglycan (GAG) concentration of ex vivo cartilage equilibrated with an anionic radiographic contrast agent, Hexabrix. Design Full-thickness fresh native (n = 19 in 3 subgroups) and trypsin-degraded (n = 6) articular cartilage blocks were imaged using micro–computed tomography (μCT) at high resolution (13.4 μm3) before and after equilibration with various Hexabrix bathing concentrations. The GAG concentration was calculated depth-dependently based on Gibbs-Donnan equilibrium theory. Analysis of variance with Tukey’s post hoc was used to test for statistical significance (P < 0.05) for effect of Hexabrix bathing concentration, and for differences in bulk and zonal GAG concentrations individually and compared between native and trypsin-degraded cartilage. Results The bulk GAG concentration was calculated to be 74.44 ± 6.09 and 11.99 ± 4.24 mg/mL for native and degraded cartilage, respectively. A statistical difference was demonstrated for bulk and zonal GAG between native and degraded cartilage (P < 0.032). A statistical difference was not demonstrated for bulk GAG when comparing Hexabrix bathing concentrations (P > 0.3214) for neither native nor degraded cartilage. Depth-dependent GAG analysis of native cartilage revealed a statistical difference only in the radial zone between 30% and 50% Hexabrix bathing concentrations. Conclusions This nondestructive qCECT methodology calculated the depth-dependent GAG concentration for both native and trypsin-degraded cartilage at high spatial resolution. qCECT allows for more detailed understanding of the topography and depth dependency, which could help diagnose health, degradation, and repair of native and contrived cartilage. PMID:26425259

An Analytic Solution to the Computation of Power and Sample Size for Genetic Association Studies under a Pleiotropic Mode of Inheritance.

PubMed

Gordon, Derek; Londono, Douglas; Patel, Payal; Kim, Wonkuk; Finch, Stephen J; Heiman, Gary A

2016-01-01

Our motivation here is to calculate the power of 3 statistical tests used when there are genetic traits that operate under a pleiotropic mode of inheritance and when qualitative phenotypes are defined by use of thresholds for the multiple quantitative phenotypes. Specifically, we formulate a multivariate function that provides the probability that an individual has a vector of specific quantitative trait values conditional on having a risk locus genotype, and we apply thresholds to define qualitative phenotypes (affected, unaffected) and compute penetrances and conditional genotype frequencies based on the multivariate function. We extend the analytic power and minimum-sample-size-necessary (MSSN) formulas for 2 categorical data-based tests (genotype, linear trend test [LTT]) of genetic association to the pleiotropic model. We further compare the MSSN of the genotype test and the LTT with that of a multivariate ANOVA (Pillai). We approximate the MSSN for statistics by linear models using a factorial design and ANOVA. With ANOVA decomposition, we determine which factors most significantly change the power/MSSN for all statistics. Finally, we determine which test statistics have the smallest MSSN. In this work, MSSN calculations are for 2 traits (bivariate distributions) only (for illustrative purposes). We note that the calculations may be extended to address any number of traits. Our key findings are that the genotype test usually has lower MSSN requirements than the LTT. More inclusive thresholds (top/bottom 25% vs. top/bottom 10%) have higher sample size requirements. The Pillai test has a much larger MSSN than both the genotype test and the LTT, as a result of sample selection. With these formulas, researchers can specify how many subjects they must collect to localize genes for pleiotropic phenotypes. © 2017 S. Karger AG, Basel.

Confirmatory factor analytic structure and measurement invariance of quantitative autistic traits measured by the social responsiveness scale-2.

PubMed

Frazier, Thomas W; Ratliff, Kristin R; Gruber, Chris; Zhang, Yi; Law, Paul A; Constantino, John N

2014-01-01

Understanding the factor structure of autistic symptomatology is critical to the discovery and interpretation of causal mechanisms in autism spectrum disorder. We applied confirmatory factor analysis and assessment of measurement invariance to a large (N = 9635) accumulated collection of reports on quantitative autistic traits using the Social Responsiveness Scale, representing a broad diversity of age, severity, and reporter type. A two-factor structure (corresponding to social communication impairment and restricted, repetitive behavior) as elaborated in the updated Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5) criteria for autism spectrum disorder exhibited acceptable model fit in confirmatory factor analysis. Measurement invariance was appreciable across age, sex, and reporter (self vs other), but somewhat less apparent between clinical and nonclinical populations in this sample comprised of both familial and sporadic autism spectrum disorders. The statistical power afforded by this large sample allowed relative differentiation of three factors among items encompassing social communication impairment (emotion recognition, social avoidance, and interpersonal relatedness) and two factors among items encompassing restricted, repetitive behavior (insistence on sameness and repetitive mannerisms). Cross-trait correlations remained extremely high, that is, on the order of 0.66-0.92. These data clarify domains of statistically significant factoral separation that may relate to partially-but not completely-overlapping biological mechanisms, contributing to variation in human social competency. Given such robust intercorrelations among symptom domains, understanding their co-emergence remains a high priority in conceptualizing common neural mechanisms underlying autistic syndromes.

Incorporating Functional Annotations for Fine-Mapping Causal Variants in a Bayesian Framework Using Summary Statistics.

PubMed

Chen, Wenan; McDonnell, Shannon K; Thibodeau, Stephen N; Tillmans, Lori S; Schaid, Daniel J

2016-11-01

Functional annotations have been shown to improve both the discovery power and fine-mapping accuracy in genome-wide association studies. However, the optimal strategy to incorporate the large number of existing annotations is still not clear. In this study, we propose a Bayesian framework to incorporate functional annotations in a systematic manner. We compute the maximum a posteriori solution and use cross validation to find the optimal penalty parameters. By extending our previous fine-mapping method CAVIARBF into this framework, we require only summary statistics as input. We also derived an exact calculation of Bayes factors using summary statistics for quantitative traits, which is necessary when a large proportion of trait variance is explained by the variants of interest, such as in fine mapping expression quantitative trait loci (eQTL). We compared the proposed method with PAINTOR using different strategies to combine annotations. Simulation results show that the proposed method achieves the best accuracy in identifying causal variants among the different strategies and methods compared. We also find that for annotations with moderate effects from a large annotation pool, screening annotations individually and then combining the top annotations can produce overly optimistic results. We applied these methods on two real data sets: a meta-analysis result of lipid traits and a cis-eQTL study of normal prostate tissues. For the eQTL data, incorporating annotations significantly increased the number of potential causal variants with high probabilities. Copyright © 2016 by the Genetics Society of America.

Environmental and Microbial Features Affecting Denitrification and Anammox Hotspots in an Estuarine Ecosystem

NASA Astrophysics Data System (ADS)

Lisa, J.; Song, B.; Lefcheck, J. S.; Tobias, C. R.

2016-02-01

Biogeochemical hotspots are characterized as a few sites that exhibit extremely high reaction rates relative to surrounding area, and often account for a high percentage of the overall reaction rates in an ecosystem. Criteria for quantitatively identifying these sites have not been well established. Further, the underlying mechanisms of hotspots have been described in terms of environmental conditions, with little attention paid to the microbial community. The objectives of this study were to establish quantitative criteria to identify denitrification and anammox hotspots, and determine the underlying microbial and environmental factors responsible for elevated N2 production. We used 15N isotope pairing incubation experiments to measure denitrification and anammox rates in the New River Estuary, NC. Quantitative PCR assays of nitrous oxide reductase (nosZ Clades I and II) and hydrazine oxidoreductase (hzo) genes were conducted to estimate denitrifier and anammox abundance. Structural Equation Modeling (SEM) was used to elucidate complex causal relationships between environmental and biological variables. Denitrification hotspots, quantitatively defined as statistical outliers, accounted for 35.6% total denitrification while comprising only 7.3% of the sites. Anammox hotspots,10.6% of the sites, accounted for 60.9% of total anammox. SEM revealed increased sediment organics at lower salinities supported higher functional gene abundance, which in turn resulted in higher N2 production. Surprisingly, denitrification rates were significantly and positively correlated with nosZ Clade II gene abundance, after accounting for the non-significant contributions of the naturally more abundant nosZ Clade I, and other environmental covariates. This is the first time that a quantitative definition of biogeochemical hotspots was put forth and used to determine the importance of anammox and denitrification hotspots in estuarine nitrogen removal capacity. Despite the low area coverage, denitrification and anammox hotspots are major nitrogen removal components and may play a significant role in mitigating eutrophication.

Selected Reaction Monitoring to Differentiate and Relatively Quantitate Isomers of Sulfated and Unsulfated Core 1 O-Glycans from Salivary MUC7 Protein in Rheumatoid Arthritis*

PubMed Central

Flowers, Sarah A.; Ali, Liaqat; Lane, Catherine S.; Olin, Magnus; Karlsson, Niclas G.

2013-01-01

Rheumatoid arthritis is a common and debilitating systemic inflammatory condition affecting up to 1% of the world's population. This study aimed to investigate the immunological significance of O-glycans in chronic arthritis at a local and systemic level. O-Glycans released from synovial glycoproteins during acute and chronic arthritic conditions were compared and immune-reactive glycans identified. The sulfated core 1 O-glycan (Galβ1–3GalNAcol) was immune reactive, showing a different isomeric profile in the two conditions. From acute reactive arthritis, three isomers could be sequenced, but in patients with chronic rheumatoid arthritis, only a single 3-Gal sulfate-linked isomer could be identified. The systemic significance of this glycan epitope was investigated using the salivary mucin MUC7 in patients with rheumatoid arthritis and normal controls. To analyze this low abundance glycan, a selected reaction monitoring (SRM) method was developed to differentiate and relatively quantitate the core 1 O-glycan and the sulfated core 1 O-glycan Gal- and GalNAc-linked isomers. The acquisition of highly sensitive full scan linear ion trap MS/MS spectra in addition to quantitative SRM data allowed the 3- and 6-linked Gal isomers to be differentiated. The method was used to relatively quantitate the core 1 glycans from MUC7 to identify any systemic changes in this carbohydrate epitope. A statistically significant increase in sulfation was identified in salivary MUC7 from rheumatoid arthritis patients. This suggests a potential role for this epitope in chronic inflammation. This study was able to develop an SRM approach to specifically identify and relatively quantitate sulfated core 1 isomers and the unsulfated structure. The expansion of this method may afford an avenue for the high throughput investigation of O-glycans. PMID:23457413

A quantitative approach to evolution of music and philosophy

NASA Astrophysics Data System (ADS)

Vieira, Vilson; Fabbri, Renato; Travieso, Gonzalo; Oliveira, Osvaldo N., Jr.; da Fontoura Costa, Luciano

2012-08-01

The development of new statistical and computational methods is increasingly making it possible to bridge the gap between hard sciences and humanities. In this study, we propose an approach based on a quantitative evaluation of attributes of objects in fields of humanities, from which concepts such as dialectics and opposition are formally defined mathematically. As case studies, we analyzed the temporal evolution of classical music and philosophy by obtaining data for 8 features characterizing the corresponding fields for 7 well-known composers and philosophers, which were treated with multivariate statistics and pattern recognition methods. A bootstrap method was applied to avoid statistical bias caused by the small sample data set, with which hundreds of artificial composers and philosophers were generated, influenced by the 7 names originally chosen. Upon defining indices for opposition, skewness and counter-dialectics, we confirmed the intuitive analysis of historians in that classical music evolved according to a master-apprentice tradition, while in philosophy changes were driven by opposition. Though these case studies were meant only to show the possibility of treating phenomena in humanities quantitatively, including a quantitative measure of concepts such as dialectics and opposition, the results are encouraging for further application of the approach presented here to many other areas, since it is entirely generic.

Novel benzanthrone probes for membrane and protein studies

NASA Astrophysics Data System (ADS)

Ryzhova, Olga; Vus, Kateryna; Trusova, Valeriya; Kirilova, Elena; Kirilov, Georgiy; Gorbenko, Galyna; Kinnunen, Paavo

2016-09-01

The applicability of a series of novel benzanthrone dyes to monitoring the changes in physicochemical properties of lipid bilayer and to differentiating between the native and aggregated protein states has been evaluated. Based on the quantitative parameters of the dye-membrane and dye-protein binding derived from the fluorimetric titration data, the most prospective membrane probes and amyloid tracers have been selected from the group of examined compounds. Analysis of the red edge excitation shifts of the membrane- and amyloid-bound dyes provided information on the properties of benzanthrone binding sites within the lipid and protein matrixes. To understand how amyloid specificity of benzanthrones correlates with their structure, quantitative structure activity relationship (QSAR) analysis was performed involving a range of quantum chemical molecular descriptors. A statistically significant model was obtained for predicting the sensitivity of novel benzanthrone dyes to amyloid fibrils.

Direct Assessment of the Effect of the Gly380Arg Achondroplasia Mutation on FGFR3 Dimerization Using Quantitative Imaging FRET

PubMed Central

Placone, Jesse; Hristova, Kalina

2012-01-01

The Gly380Arg mutation in FGFR3 is the genetic cause for achondroplasia (ACH), the most common form of human dwarfism. The mutation has been proposed to increase FGFR3 dimerization, but the dimerization propensities of wild-type and mutant FGFR3 have not been compared. Here we use quantitative imaging FRET to characterize the dimerization of wild-type FGFR3 and the ACH mutant in plasma membrane-derived vesicles from HEK293T cells. We demonstrate a small, but statistically significant increase in FGFR3 dimerization due to the ACH mutation. The data are consistent with the idea that the ACH mutation causes a structural change which affects both the stability and the activity of FGFR3 dimers in the absence of ligand. PMID:23056398

Evaluation of life and death studies course on attitudes toward life and death among nursing students.

PubMed

Hwang, Huei-Lih; Lin, Huey-Shyan; Chen, Wen-Tin

2005-12-01

The aim of this study was to evaluate attitudes toward life and death among nursing students after attending the life and death studies (LDS) program. Both qualitative and quantitative methods were used to collect data. The pretest-posttest control group design randomly assigned students to an experimental (n = 47) or control group (n = 49). The 13-week course included lectures, video appraisal, games, simulations, films, books, assignments and group sharing. Statistical and content analysis were used to analyze qualitative and quantitative data. The findings showed a significant improvement in perception of the meaningfulness of life in four categories of improvement: expanded viewpoint, sadness about death, treating life sincerely, and instilling hope in life. The qualitative data indicated that a positive change in meaning of life was associated with interaction with others and self-reflection.

Evaluation of the ecological relevance of mysid toxicity tests using population modeling techniques

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

Kuhn-Hines, A.; Munns, W.R. Jr.; Lussier, S.

1995-12-31

A number of acute and chronic bioassay statistics are used to evaluate the toxicity and risks of chemical stressors to the mysid shrimp, Mysidopsis bahia. These include LC{sub 50}S from acute tests, NOECs from 7-day and life-cycle tests, and the US EPA Water Quality Criteria Criterion Continuous Concentrations (CCC). Because these statistics are generated from endpoints which focus upon the responses of individual organisms, their relationships to significant effects at higher levels of ecological organization are unknown. This study was conducted to evaluate the quantitative relationships between toxicity test statistics and a concentration-based statistic derived from exposure-response models describing populationmore » growth rate ({lambda}) to stressor concentration. This statistic, C{sup {sm_bullet}} (concentration where {lambda} = I, zero population growth) describes the concentration above which mysid populations are projected to decline in abundance as determined using population modeling techniques. An analysis of M. bahia responses to 9 metals and 9 organic contaminants indicated the NOEC from life-cycle tests to be the best predictor of C{sup {sm_bullet}}, although the acute LC{sub 50} predicted population-level response surprisingly well. These analyses provide useful information regarding uncertainties of extrapolation among test statistics in assessments of ecological risk.« less

Statistical label fusion with hierarchical performance models

PubMed Central

Asman, Andrew J.; Dagley, Alexander S.; Landman, Bennett A.

2014-01-01

Label fusion is a critical step in many image segmentation frameworks (e.g., multi-atlas segmentation) as it provides a mechanism for generalizing a collection of labeled examples into a single estimate of the underlying segmentation. In the multi-label case, typical label fusion algorithms treat all labels equally – fully neglecting the known, yet complex, anatomical relationships exhibited in the data. To address this problem, we propose a generalized statistical fusion framework using hierarchical models of rater performance. Building on the seminal work in statistical fusion, we reformulate the traditional rater performance model from a multi-tiered hierarchical perspective. This new approach provides a natural framework for leveraging known anatomical relationships and accurately modeling the types of errors that raters (or atlases) make within a hierarchically consistent formulation. Herein, we describe several contributions. First, we derive a theoretical advancement to the statistical fusion framework that enables the simultaneous estimation of multiple (hierarchical) performance models within the statistical fusion context. Second, we demonstrate that the proposed hierarchical formulation is highly amenable to the state-of-the-art advancements that have been made to the statistical fusion framework. Lastly, in an empirical whole-brain segmentation task we demonstrate substantial qualitative and significant quantitative improvement in overall segmentation accuracy. PMID:24817809

Cutaneous Microenvironment of Human Immunodeficiency Virus (HIV)-Seropositive and HIV-Seronegative Individuals, with Special Reference to Staphylococcus aureus Colonization

PubMed Central

Shapiro, Michael; Smith, Kathleen J.; James, William D.; Giblin, Walter J.; Margolis, David J.; Foglia, Arlene N.; McGinley, Kenneth; Leyden, James J.

2000-01-01

A cross-sectional quantitative study of cutaneous bacterial and yeast flora at seven body sites in 99 human immunodeficiency virus-seropositive and 50 seronegative military personnel was performed. Statistically significant differences in carriage rates were only observed for Staphylococcus aureus on the foreheads of seropositive individuals. Seronegative individuals demonstrated staphylococcal carriage rates 1.3 to 2 times as great as those of historical controls (defined as healthy individuals not receiving any medications) at five of six body sites. We conclude that seropositive military personnel do not exhibit statistically significant elevations in densities and carriage rates of the microorganisms examined (except Staphylococcus aureus), relative to seronegative individuals. Seropositive individuals may be predisposed to staphylococcal carriage. The elevated staphylococcal carriage rates of military personnel undergoing basic training warrants a formal evaluation of the impact of training exercises on cutaneous flora. The information gained may serve to limit the spread of infection during training exercises and battlefield conditions. PMID:10970352

Reducing child mortality in Nigeria: a case study of immunization and systemic factors.

PubMed

Nwogu, Rufus; Ngowu, Rufus; Larson, James S; Kim, Min Su

2008-07-01

The purpose of the study is to assess the outcome of the Expanded Program on Immunization (EPI) in Nigeria, as well as to examine systemic factors influencing its high under-five mortality rate (UFMR). The principal objective of the EPI program when it was implemented in 1978 was to reduce mortality, morbidity and disability associated with six vaccine preventable diseases namely tuberculosis, tetanus, diphtheria, measles, pertussis and poliomyelitis. The methodological approach to this study is quantitative, using secondary time series data from 1970 to 2003. The study tested three hypotheses using time series multiple regression analysis with autocorrelation adjustment as a statistical model. The results showed that the EPI program had little effect on UFMR in Nigeria. Only the literacy rate and domestic spending on healthcare had statistically significant effects on the UFMR. The military government was not a significant factor in reducing or increasing the UFMR. It appears that Nigeria needs a unified approach to healthcare delivery, rather than fragmented programs, to overcome cultural and political divisions in society.

Blended Learning Versus Traditional Lecture in Introductory Nursing Pathophysiology Courses.

PubMed

Blissitt, Andrea Marie

2016-04-01

Currently, many undergraduate nursing courses use blended-learning course formats with success; however, little evidence exists that supports the use of blended formats in introductory pathophysiology courses. The purpose of this study was to compare the scores on pre- and posttests and course satisfaction between traditional and blended course formats in an introductory nursing pathophysiology course. This study used a quantitative, quasi-experimental, nonrandomized control group, pretest-posttest design. Analysis of covariance compared pre- and posttest scores, and a t test for independent samples compared students' reported course satisfaction of the traditional and blended course formats. Results indicated that the differences in posttest scores were not statistically significant between groups. Students in the traditional group reported statistically significantly higher satisfaction ratings than students in the blended group. The results of this study support the need for further research of using blended learning in introductory pathophysiology courses in undergraduate baccalaureate nursing programs. Further investigation into how satisfaction is affected by course formats is needed. Copyright 2016, SLACK Incorporated.

[Quantitative and qualitative changes in the sex chromatin of diabetic women of different ages].

PubMed

Kaiumov, E G; Dmitrieva, E N

1975-01-01

There was revealed a statistically significant reduction in the frequency of occurrence of sex chromatine (SC) in the patients (female) suffering from diabetes mellitus aged from 15 to 65 years before the treatment in comparison with the healthy women. After the compensation of the carbohydrate metabolism there was noted its further reduction in the patients aged from 25 to 65 years. In 15-65-year women who contracted diabetes mellitus there was an increase in the circular form of the SC bodies looking like thickenings of the nuclear membrane; SC bodies of round shape enlarged as well in women aged from 25 to 65 years. Oval, triangular and semicircular forms decreased in all the age groups. After the compensation of the carbohydrate metabolism the content of the SC bodies of various shapes remained the same as at the beginning of the disease without returning to the normal level. The area of the SC bodies enlargement was statistically significant in women who fell ill with diabetes mellitus.

Real-time observational evidence of changing Asian dust morphology with the mixing of heavy anthropogenic pollution

NASA Astrophysics Data System (ADS)

Pan, X.; Uno, I.; Wang, Z.; Nishizawa, T.; Sugimoto, N.; Yamamoto, S.; Kobayashi, H.; Sun, Y.; Fu, P.; Tang, X.; Wang, Z.

2017-12-01

Natural mineral dust and heavy anthropogenic pollution and its complex interactions cause significant environmental problems in East Asia. Due to restrictions of observing technique, real-time morphological change in Asian dust particles owing to coating process of anthropogenic pollutants is still statistically unclear. Here, we first used a newly developed, single-particle polarization detector and quantitatively investigate the evolution of the polarization property of backscattering light reflected from dust particle as they were mixing with anthropogenic pollutants in North China. The decrease in observed depolarization ratio is mainly attributed to the decrease of aspect ratio of the dust particles as a result of continuous coating processes. Hygroscopic growth of Calcium nitrate (Ca(NO3)2) on the surface of the dust particles played a vital role, particularly when they are stagnant in the polluted region with high RH conditions. Reliable statistics highlight the significant importance of internally mixed, `quasi-spherical' Asian dust particles, which markedly act as cloud condensation nuclei and exert regional climate change.

Real-time observational evidence of changing Asian dust morphology with the mixing of heavy anthropogenic pollution.

PubMed

Pan, Xiaole; Uno, Itsushi; Wang, Zhe; Nishizawa, Tomoaki; Sugimoto, Nobuo; Yamamoto, Shigekazu; Kobayashi, Hiroshi; Sun, Yele; Fu, Pingqing; Tang, Xiao; Wang, Zifa

2017-03-23

Natural mineral dust and heavy anthropogenic pollution and its complex interactions cause significant environmental problems in East Asia. Due to restrictions of observing technique, real-time morphological change in Asian dust particles owing to coating process of anthropogenic pollutants is still statistically unclear. Here, we first used a newly developed, single-particle polarization detector and quantitatively investigate the evolution of the polarization property of backscattering light reflected from dust particle as they were mixing with anthropogenic pollutants in North China. The decrease in observed depolarization ratio is mainly attributed to the decrease of aspect ratio of the dust particles as a result of continuous coating processes. Hygroscopic growth of Calcium nitrate (Ca(NO 3 ) 2 ) on the surface of the dust particles played a vital role, particularly when they are stagnant in the polluted region with high RH conditions. Reliable statistics highlight the significant importance of internally mixed, 'quasi-spherical' Asian dust particles, which markedly act as cloud condensation nuclei and exert regional climate change.

Quantitative EEG analysis of the maturational changes associated with childhood absence epilepsy

NASA Astrophysics Data System (ADS)

Rosso, O. A.; Hyslop, W.; Gerlach, R.; Smith, R. L. L.; Rostas, J. A. P.; Hunter, M.

2005-10-01

This study aimed to examine the background electroencephalography (EEG) in children with childhood absence epilepsy, a condition whose presentation has strong developmental links. EEG hallmarks of absence seizure activity are widely accepted and there is recognition that the bulk of inter-ictal EEG in this group is normal to the naked eye. This multidisciplinary study aimed to use the normalized total wavelet entropy (NTWS) (Signal Processing 83 (2003) 1275) to examine the background EEG of those patients demonstrating absence seizure activity, and compare it with children without absence epilepsy. This calculation can be used to define the degree of order in a system, with higher levels of entropy indicating a more disordered (chaotic) system. Results were subjected to further statistical analyses of significance. Entropy values were calculated for patients versus controls. For all channels combined, patients with absence epilepsy showed (statistically significant) lower entropy values than controls. The size of the difference in entropy values was not uniform, with certain EEG electrodes consistently showing greater differences than others.

Subjective Burden and Depression in Mothers of Children with Autism Spectrum Disorder in India: Moderating Effect of Social Support.

PubMed

Singh, Prerna; Ghosh, Subharati; Nandi, Subhrangshu

2017-10-01

The quantitative study assessed subjective burden, depression, and the moderating effect of social support in mothers of children with autism spectrum disorder (ASD) in India. Seventy mothers were interviewed using a structured interview schedule, which measured their subjective burden, depression, and social support from family, friends, and significant others. Data was analyzed using descriptive statistics and multiple regression analysis with interaction terms. Half of the mothers in the study reported depression of clinical significance. Higher subjective burden significantly predicted higher depression. Of the three sources of support, only medium/high family support had a direct impact on depression and also moderated the impact of the subjective burden of depression. Implications for practice and policy are discussed.

Dragon boat racing and health-related quality of life of breast cancer survivors: a mixed methods evaluation.

PubMed

Ray, Heather A; Verhoef, Marja J

2013-08-05

Breast cancer survivors who participate in physical activity (PA) are reported to experience improved health-related quality of life (HRQOL). However, the quantitative research exploring the relationship between the team-based activity of dragon boat racing and the HRQOL of breast cancer survivors is limited. Given the rising number of breast cancer survivors, and their growing attraction to dragon boating, further exploration of the influence of this activity on HRQOL is warranted. This study is designed to: 1) quantitatively assess whether and how breast cancer survivors' participation in a season of dragon boat racing is related to HRQOL and 2) qualitatively explore the survivors' lived experience of dragon boating and how and why this experience is perceived to influence HRQOL. A mixed methods sequential explanatory design was used with the purpose of complementing quantitative findings with qualitative data. Quantitative data measuring HRQOL were collected at baseline and post-season (N=100); semi-structured qualitative interviews were used to elicit a personal account of the dragon boat experience (N=15). Statistically significant improvements were shown for HRQOL, physical, functional, emotional and spiritual well-being, breast cancer-specific concerns and cancer-related fatigue. A trend towards significance was shown for social/family well-being. Qualitative data elaborated on the quantitative findings, greatly enhancing the understanding of how and why dragon boat racing influences HRQOL. The use of a mixed methods design effectively captured the complex yet positive influence of dragon boating on survivor HRQOL. These findings contribute to a growing body of literature supporting the value of dragon boat racing as a viable PA intervention for enhancing survivor HRQOL.

Asian and Siberian ginseng as a potential modulator of immune function: an in vitro cytokine study using mouse macrophages.

PubMed

Wang, Huamin; Actor, Jeffrey K; Indrigo, Jessica; Olsen, Margaret; Dasgupta, Amitava

2003-01-01

Ginseng is a widely used herbal product in China, other Asian countries, and in the Unites States. There is a traditional belief that ginseng stimulates immune functions. In this study, the innate effects of Asian and Siberian ginsengs on cytokines and chemokines produced by cultured macrophages were examined. The effects of Asian and Siberian ginseng on cytokines and chemokines produced by cultured macrophages were examined. Mouse macrophages (J774A.1) were incubated with Asian or Siberian ginseng at varying concentrations (1, 10, 100, and 1000 microg/ml) for 24 h and then harvested for RNA isolation. The expression levels of IL-1beta, IL-12, TNF-alpha, MIP-1 alpha, and MIP-2 mRNA were measured by quantitative PCR. Our data showed that Asian ginseng induced a statistically significant increase in IL-12 expression at both mRNA and protein levels. However, the minor twofold increase is probably biologically insignificant. No significant increase of IL-12 by Siberian ginseng was observed at any dose level studied. No significant change in IL-1beta, IL-15, TNF-alpha, or MIP-1alpha mRNA was observed by either Asian or Siberian ginseng treatment. Our data showed statistically significant differential regulation of IL-12 by Asian ginseng. Siberian ginseng did not show a statistically significant increase. We conclude that both Asian ginseng and Siberian ginseng cannot significantly stimulate innate macrophage immune functions that influence cellular immune responses. Therefore, contrary to the popular belief, Asian and Siberian ginseng may not stimulate immune function.

Quantitative Methods for Analysing Joint Questionnaire Data: Exploring the Role of Joint in Force Design

DTIC Science & Technology

2015-08-01

the nine questions. The Statistical Package for the Social Sciences ( SPSS ) [11] was used to conduct statistical analysis on the sample. Two types...constructs. SPSS was again used to conduct statistical analysis on the sample. This time factor analysis was conducted. Factor analysis attempts to...Business Research Methods and Statistics using SPSS . P432. 11 IBM SPSS Statistics . (2012) 12 Burns, R.B., Burns, R.A. (2008) ‘Business Research

Comparison of the effect of multiple intelligence pedagogy and traditional pedagogy on grade 5 students' achievement and attitudes towards science

NASA Astrophysics Data System (ADS)

Mussen, Kimberly S.

This quantitative research study evaluated the effectiveness of employing pedagogy based on the theory of multiple intelligences (MI). Currently, not all students are performing at the rate mandated by the government. When schools do not meet the required state standards, the school is labeled as not achieving adequate yearly progress (AYP), which may lead to the loss of funding. Any school not achieving AYP would be interested in this study. Due to low state standardized test scores in the district for science, student achievement and attitudes towards learning science were evaluated on a pretest, posttest, essay question, and one attitudinal survey. Statistical significance existed on one of the four research questions. Utilizing the Analysis of Covariance (ANCOVA) for data analysis, student attitudes towards learning science were statically significant in the MI (experimental) group. No statistical significance was found in student achievement on the posttest, delayed posttest, or the essay question test. Social change can result from this study because studying the effects of the multiple intelligence theory incorporated into classroom instruction can have significant effect on how children learn, allowing them to compete in a knowledge society.

EvolQG - An R package for evolutionary quantitative genetics

PubMed Central

Melo, Diogo; Garcia, Guilherme; Hubbe, Alex; Assis, Ana Paula; Marroig, Gabriel

2016-01-01

We present an open source package for performing evolutionary quantitative genetics analyses in the R environment for statistical computing. Evolutionary theory shows that evolution depends critically on the available variation in a given population. When dealing with many quantitative traits this variation is expressed in the form of a covariance matrix, particularly the additive genetic covariance matrix or sometimes the phenotypic matrix, when the genetic matrix is unavailable and there is evidence the phenotypic matrix is sufficiently similar to the genetic matrix. Given this mathematical representation of available variation, the \\textbf{EvolQG} package provides functions for calculation of relevant evolutionary statistics; estimation of sampling error; corrections for this error; matrix comparison via correlations, distances and matrix decomposition; analysis of modularity patterns; and functions for testing evolutionary hypotheses on taxa diversification. PMID:27785352

Maxillary sinus augmentation by crestal access: a retrospective study on cavity size and outcome correlation.

PubMed

Spinato, Sergio; Bernardello, Fabio; Galindo-Moreno, Pablo; Zaffe, Davide

2015-12-01

Cone-beam computed tomography (CBCT) and radiographic outcomes of crestal sinus elevation, performed using mineralized human bone allograft, were analyzed to correlate results with maxillary sinus size. A total of 60 sinus augmentations in 60 patients, with initial bone ≤5 mm, were performed. Digital radiographs were taken at surgical implant placement time up to post-prosthetic loading follow-up (12-72 months), when CBCT evaluation was carried out. Marginal bone loss (MBL) was radiographically analyzed at 6 months and follow-up time post-loading. Sinus size (BPD), implant distance from palatal (PID) and buccal wall (BID), and absence of bone coverage of implant (intra-sinus bone loss--IBL) were evaluated and statistically evaluated by ANOVA and linear regression analyses. MBL increased as a function of time. MBL at final follow-up was statistically associated with MBL at 6 months. A statistically significant correlation of IBL with wall distance and of IBL/mm with time was identified with greater values in wide sinuses (WS ≥ 13.27 mm) than in narrow sinuses (NS < 13.27 mm). This study is the first quantitative and statistically significant confirmation that crestal technique with residual ridge height <5 mm is more appropriate and predictable, in terms of intra-sinus bone coverage, in narrow than in WS. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

MCM - 2 and Ki - 67 as proliferation markers in renal cell carcinoma: A quantitative and semi - quantitative analysis

PubMed Central

Mehdi, Muhammad Zain; Nagi, Abdul Hanan; Naseem, Nadia

2016-01-01

ABSTRACT Introduction/Background: Fuhrman nuclear grade is the most important histological parameter to predict prognosis in a patient of renal cell carcinoma (RCC). However, it suffers from inter-observer and intra-observer variation giving rise to need of a parameter that not only correlates with nuclear grade but is also objective and reproducible. Proliferation is the measure of aggressiveness of a tumour and it is strongly correlated with Fuhrman nuclear grade, clinical survival and recurrence in RCC. Ki-67 is conventionally used to assess proliferation. Mini-chromosome maintenance 2 (MCM-2) is a lesser known marker of proliferation and identifies a greater proliferation faction. This study was designed to assess the prognostic significance of MCM-2 by comparing it with Fuhrman nuclear grade and Ki-67. Material and Methods: n=50 cases of various ages, stages, histological subtypes and grades of RCC were selected for this study. Immunohistochemical staining using Ki-67(MIB-1, Mouse monoclonal antibody, Dako) and MCM-2 (Mouse monoclonal antibody, Thermo) was performed on the paraffin embedded blocks in the department of Morbid anatomy and Histopathology, University of Health Sciences, Lahore. Labeling indices (LI) were determined by two pathologists independently using quantitative and semi-quantitative analysis. Statistical analysis was carried out using SPSS 20.0. Kruskall-Wallis test was used to determine a correlation of proliferation markers with grade, and Pearson's correlate was used to determine correlation between the two proliferation markers. Results: Labeling index of MCM-2 (median=24.29%) was found to be much higher than Ki-67(median=13.05%). Both markers were significantly related with grade (p=0.00; Kruskall-Wallis test). LI of MCM-2 was found to correlate significantly with LI of Ki-67(r=0.0934;p=0.01 with Pearson's correlate). Results of semi-quantitative analysis correlated well with quantitative analysis. Conclusion: Both Ki-67 and MCM-2 are markers of proliferation which are closely linked to grade. Therefore, they can act as surrogate markers for grade in a manner that is more objective and reproducible. PMID:27532114

MCM - 2 and Ki - 67 as proliferation markers in renal cell carcinoma: A quantitative and semi - quantitative analysis.

PubMed

Mehdi, Muhammad Zain; Nagi, Abdul Hanan; Naseem, Nadia

2016-01-01

Fuhrman nuclear grade is the most important histological parameter to predict prognosis in a patient of renal cell carcinoma (RCC). However, it suffers from inter-observer and intra-observer variation giving rise to need of a parameter that not only correlates with nuclear grade but is also objective and reproducible. Proliferation is the measure of aggressiveness of a tumour and it is strongly correlated with Fuhrman nuclear grade, clinical survival and recurrence in RCC. Ki-67 is conventionally used to assess proliferation. Mini-chromosome maintenance 2 (MCM-2) is a lesser known marker of proliferation and identifies a greater proliferation faction. This study was designed to assess the prognostic significance of MCM-2 by comparing it with Fuhrman nuclear grade and Ki-67. n=50 cases of various ages, stages, histological subtypes and grades of RCC were selected for this study. Immunohistochemical staining using Ki-67(MIB-1, Mouse monoclonal antibody, Dako) and MCM-2 (Mouse monoclonal antibody, Thermo) was performed on the paraffin embedded blocks in the department of Morbid anatomy and Histopathology, University of Health Sciences, Lahore. Labeling indices (LI) were determined by two pathologists independently using quantitative and semi-quantitative analysis. Statistical analysis was carried out using SPSS 20.0. Kruskall-Wallis test was used to determine a correlation of proliferation markers with grade, and Pearson's correlate was used to determine correlation between the two proliferation markers. Labeling index of MCM-2 (median=24.29%) was found to be much higher than Ki-67(median=13.05%). Both markers were significantly related with grade (p=0.00; Kruskall-Wallis test). LI of MCM-2 was found to correlate significantly with LI of Ki-67(r=0.0934;p=0.01 with Pearson's correlate). Results of semi-quantitative analysis correlated well with quantitative analysis. Both Ki-67 and MCM-2 are markers of proliferation which are closely linked to grade. Therefore, they can act as surrogate markers for grade in a manner that is more objective and reproducible. Copyright® by the International Brazilian Journal of Urology.

Matrix metalloproteinases and educational attainment in refractive error: evidence of gene-environment interactions in the AREDS study

PubMed Central

Wojciechowski, Robert; Yee, Stephanie S.; Simpson, Claire L.; Bailey-Wilson, Joan E.; Stambolian, Dwight

2012-01-01

Purpose A previous study of Old Order Amish families has shown association of ocular refraction with markers proximal to matrix metalloproteinase (MMP) genes MMP1 and MMP10 and intragenic to MMP2. We conducted a candidate gene replication study of association between refraction and single nucleotide polymorphisms (SNPs) within these genomic regions. Design Candidate gene genetic association study. Participants 2,000 participants drawn from the Age Related Eye Disease Study (AREDS) were chosen for genotyping. After quality control filtering, 1912 individuals were available for analysis. Methods Microarray genotyping was performed using the HumanOmni 2.5 bead array. SNPs originally typed in the previous Amish association study were extracted for analysis. In addition, haplotype tagging SNPs were genotyped using TaqMan assays. Quantitative trait association analyses of mean spherical equivalent refraction (MSE) were performed on 30 markers using linear regression models and an additive genetic risk model, while adjusting for age, sex, education, and population substructure. Post-hoc analyses were performed after stratifying on a dichotomous education variable. Pointwise (P-emp) and multiple-test study-wise (P-multi) significance levels were calculated empirically through permutation. Main outcome measures MSE was used as a quantitative measure of ocular refraction. Results The mean age and ocular refraction were 68 years (SD=4.7) and +0.55 D (SD=2.14), respectively. Pointwise statistical significance was obtained for rs1939008 (P-emp=0.0326). No SNP attained statistical significance after correcting for multiple testing. In stratified analyses, multiple SNPs reached pointwise significance in the lower-education group: 2 of these were statistically significant after multiple testing correction. The two highest-ranking SNPs in Amish families (rs1939008 and rs9928731) showed pointwise P-emp<0.01 in the lower-education stratum of AREDS participants. Conclusions We show suggestive evidence of replication of an association signal for ocular refraction to a marker between MMP1 and MMP10. We also provide evidence of a gene-environment interaction between previously-reported markers and education on refractive error. Variants in MMP1- MMP10 and MMP2 regions appear to affect population variation in ocular refraction in environmental conditions less favorable for myopia development. PMID:23098370

How the Mastery Rubric for Statistical Literacy Can Generate Actionable Evidence about Statistical and Quantitative Learning Outcomes

ERIC Educational Resources Information Center

Tractenberg, Rochelle E.

2017-01-01

Statistical literacy is essential to an informed citizenry; and two emerging trends highlight a growing need for training that achieves this literacy. The first trend is towards "big" data: while automated analyses can exploit massive amounts of data, the interpretation--and possibly more importantly, the replication--of results are…

On a Calculus-based Statistics Course for Life Science Students

PubMed Central

2010-01-01

The choice of pedagogy in statistics should take advantage of the quantitative capabilities and scientific background of the students. In this article, we propose a model for a statistics course that assumes student competency in calculus and a broadening knowledge in biology. We illustrate our methods and practices through examples from the curriculum. PMID:20810962

A Framework for Establishing Standard Reference Scale of Texture by Multivariate Statistical Analysis Based on Instrumental Measurement and Sensory Evaluation.

PubMed

Zhi, Ruicong; Zhao, Lei; Xie, Nan; Wang, Houyin; Shi, Bolin; Shi, Jingye

2016-01-13

A framework of establishing standard reference scale (texture) is proposed by multivariate statistical analysis according to instrumental measurement and sensory evaluation. Multivariate statistical analysis is conducted to rapidly select typical reference samples with characteristics of universality, representativeness, stability, substitutability, and traceability. The reasonableness of the framework method is verified by establishing standard reference scale of texture attribute (hardness) with Chinese well-known food. More than 100 food products in 16 categories were tested using instrumental measurement (TPA test), and the result was analyzed with clustering analysis, principal component analysis, relative standard deviation, and analysis of variance. As a result, nine kinds of foods were determined to construct the hardness standard reference scale. The results indicate that the regression coefficient between the estimated sensory value and the instrumentally measured value is significant (R(2) = 0.9765), which fits well with Stevens's theory. The research provides reliable a theoretical basis and practical guide for quantitative standard reference scale establishment on food texture characteristics.

Fundamental quantitative security in quantum key generation

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

Yuen, Horace P.

2010-12-15

We analyze the fundamental security significance of the quantitative criteria on the final generated key K in quantum key generation including the quantum criterion d, the attacker's mutual information on K, and the statistical distance between her distribution on K and the uniform distribution. For operational significance a criterion has to produce a guarantee on the attacker's probability of correctly estimating some portions of K from her measurement, in particular her maximum probability of identifying the whole K. We distinguish between the raw security of K when the attacker just gets at K before it is used in a cryptographicmore » context and its composition security when the attacker may gain further information during its actual use to help get at K. We compare both of these securities of K to those obtainable from conventional key expansion with a symmetric key cipher. It is pointed out that a common belief in the superior security of a quantum generated K is based on an incorrect interpretation of d which cannot be true, and the security significance of d is uncertain. Generally, the quantum key distribution key K has no composition security guarantee and its raw security guarantee from concrete protocols is worse than that of conventional ciphers. Furthermore, for both raw and composition security there is an exponential catch-up problem that would make it difficult to quantitatively improve the security of K in a realistic protocol. Some possible ways to deal with the situation are suggested.« less

Quantile-based permutation thresholds for quantitative trait loci hotspots.

PubMed

Neto, Elias Chaibub; Keller, Mark P; Broman, Andrew F; Attie, Alan D; Jansen, Ritsert C; Broman, Karl W; Yandell, Brian S

2012-08-01

Quantitative trait loci (QTL) hotspots (genomic locations affecting many traits) are a common feature in genetical genomics studies and are biologically interesting since they may harbor critical regulators. Therefore, statistical procedures to assess the significance of hotspots are of key importance. One approach, randomly allocating observed QTL across the genomic locations separately by trait, implicitly assumes all traits are uncorrelated. Recently, an empirical test for QTL hotspots was proposed on the basis of the number of traits that exceed a predetermined LOD value, such as the standard permutation LOD threshold. The permutation null distribution of the maximum number of traits across all genomic locations preserves the correlation structure among the phenotypes, avoiding the detection of spurious hotspots due to nongenetic correlation induced by uncontrolled environmental factors and unmeasured variables. However, by considering only the number of traits above a threshold, without accounting for the magnitude of the LOD scores, relevant information is lost. In particular, biologically interesting hotspots composed of a moderate to small number of traits with strong LOD scores may be neglected as nonsignificant. In this article we propose a quantile-based permutation approach that simultaneously accounts for the number and the LOD scores of traits within the hotspots. By considering a sliding scale of mapping thresholds, our method can assess the statistical significance of both small and large hotspots. Although the proposed approach can be applied to any type of heritable high-volume "omic" data set, we restrict our attention to expression (e)QTL analysis. We assess and compare the performances of these three methods in simulations and we illustrate how our approach can effectively assess the significance of moderate and small hotspots with strong LOD scores in a yeast expression data set.

A study of the relationships between "highly qualified" status, instructional practices, and students' science achievement in three high poverty Louisiana school systems

NASA Astrophysics Data System (ADS)

Clayton, Michelle

Using a mixed methods research design, the author examined the relationships between "highly qualified" status, instructional practices, and students' science achievement for six third grade teachers in three high poverty Louisiana school systems. The study analyzed qualitative and quantitative data for three science classes taught by "highly qualified" teachers and three science classes taught by "non-highly qualified" teachers. The qualitative portion of the study was conducted through classroom observations, teacher interviews, and lesson plan reviews. The qualitative data was coded and triangulated to determine whether the instructional practices of each teacher were more "teacher-centered" or "student-centered." The qualitative data analysis indicated various patterns and consistencies in the instructional practices used by the "highly qualified" and "non-highly qualified" teachers selected for this study. The quantitative portion of the study involved analysis of the students' science achievement data for the six third grade science teachers selected for the study. Science achievement was measured by the third grade Integrated Louisiana Education Assessment Program (iLEAP) scores. A two-way ANOVA indicated that there were statistically significant differences in the mean scores of the three high poverty Louisiana school systems as well as the students taught by "highly qualified" and "non-highly qualified" teachers and the interactions between the two: F(2, 123) = 46.99, p < 0.01; F(1, 123) = 4.54, p = 0.035; F(2, 123) = 3.73, p = 0.027. A separate one-way ANOVA indicated that statistically significant differences existed between the six participating teachers in the study: F (5, 123) = 20.386, p < 0.01). Tukey's HSD post-hoc tests and homogeneous subset analyses were conducted in order to determine which teachers' scores significantly differed from each other.

The Potential of Self-assembling Peptides for Enhancement of In Vitro Remineralisation of White Spot Lesions as Measured by Quantitative Laser Fluorescence.

PubMed

Golland, Luca; Schmidlin, Patrick R; Schätzle, Marc

To test the remineralisation potential of a single application of self-assembling peptides or acidic fluoride solution using quantitative light-induced fluorescence (QLF) in vitro. Bovine enamel disks were prepared, and white spot lesions were created on one half of the disk with an acidic buffer solution. After demineralisation, disks were allocated into three groups of 11 specimens each. Group A served as a control group and received no treatment. Group B had a single application of fluoride, and group C was treated once with self-assembling peptides. All disks were embedded in a plastic mold (diameter 15 mm, height 9 mm) with an a-silicone, and remineralisation was initiated using a pH-cycling protocol for five days. Four experimental regions on each disk were measured prior to the start of the study (T0), after demineralisation (T1) and after the remineralisation process (T2) using QLF. After demineralisation, all areas showed a distinct loss of fluorescence, with no statistically significant difference between the groups (ΔF from -69.3 to -10.2). After remineralisation, samples of group B (treated with fluoride) showed a statistically significant fluorescence increase (ΔF from T1 to T2 15.2 ± 7.3) indicating remineralisation, whereas the samples of control group A and group C (treated with self-assembling peptides) showed no significant changes in ΔF of 1.1 ± 1.9 and 2.5 ± 1.9, respectively. Application of self-assembling peptides on demineralised bovine enamel did not lead to increased fluorescence using QLF, indicating either lack of remineralisation or irregular crystals. Increased fluorescence using QLF indicated mineral gain following a single application of a highly concentrated fluoride.

Behavioral Assembly Required: Particularly for Quantitative Courses

ERIC Educational Resources Information Center

Mazen, Abdelmagid

2008-01-01

This article integrates behavioral approaches into the teaching and learning of quantitative subjects with application to statistics. Focusing on the emotional component of learning, the article presents a system dynamic model that provides descriptive and prescriptive accounts of learners' anxiety. Metaphors and the metaphorizing process are…

Power Analysis Software for Educational Researchers

ERIC Educational Resources Information Center

Peng, Chao-Ying Joanne; Long, Haiying; Abaci, Serdar

2012-01-01

Given the importance of statistical power analysis in quantitative research and the repeated emphasis on it by American Educational Research Association/American Psychological Association journals, the authors examined the reporting practice of power analysis by the quantitative studies published in 12 education/psychology journals between 2005…

LANDSCAPE STRUCTURE AND ESTUARINE CONDITION IN THE MID-ATLANTIC REGION OF THE UNITED STATES: I. DEVELOPING QUANTITATIVE RELATIONSHIPS

EPA Science Inventory

In a previously published study, quantitative relationships were developed between landscape metrics and sediment contamination for 25 small estuarine systems within Chesapeake Bay. Nonparametric statistical analysis (rank transformation) was used to develop an empirical relation...

Dual-energy CT iodine maps as an alternative quantitative imaging biomarker to abdominal CT perfusion: determination of appropriate trigger delays for acquisition using bolus tracking.

PubMed

Skornitzke, Stephan; Fritz, Franziska; Mayer, Philipp; Koell, Marco; Hansen, Jens; Pahn, Gregor; Hackert, Thilo; Kauczor, Hans-Ulrich; Stiller, Wolfram

2018-05-01

Quantitative evaluation of different bolus tracking trigger delays for acquisition of dual energy (DE) CT iodine maps as an alternative to CT perfusion. Prior to this retrospective analysis of prospectively acquired data, DECT perfusion sequences were dynamically acquired in 22 patients with pancreatic carcinoma using dual source CT at 80/140 kV p with tin filtration. After deformable motion-correction, perfusion maps of blood flow (BF) were calculated from 80 kV p image series of DECT, and iodine maps were calculated for each of the 34 DECT acquisitions per patient. BF and iodine concentrations were measured in healthy pancreatic tissue and carcinoma. To evaluate potential DECT acquisition triggered by bolus tracking, measured iodine concentrations from the 34 DECT acquisitions per patient corresponding to different trigger delays were assessed for correlation to BF and intergroup differences between tissue types depending on acquisition time. Average BF measured in healthy pancreatic tissue and carcinoma was 87.6 ± 28.4 and 38.6 ± 22.2 ml/100 ml min -1 , respectively. Correlation between iodine concentrations and BF was statistically significant for bolus tracking with trigger delay greater than 0 s (r max = 0.89; p < 0.05). Differences in iodine concentrations between healthy pancreatic tissue and carcinoma were statistically significant for DECT acquisitions corresponding to trigger delays of 15-21 s (p < 0.05). An acquisition window between 15 and 21 s after exceeding bolus tracking threshold shows promising results for acquisition of DECT iodine maps as an alternative to CT perfusion measurements of BF. Advances in knowledge: After clinical validation, DECT iodine maps of pancreas acquired using bolus tracking with appropriate trigger delay as determined in this study could offer an alternative quantitative imaging biomarker providing functional information for tumor assessment at reduced patient radiation exposure compared to CT perfusion measurements of BF.

Alternative and traditional assessments: Their comparative impact on students' attitudes and science learning outcomes. An exploratory study

NASA Astrophysics Data System (ADS)

Century, Daisy Nelson

This probing study focused on alternative and traditional assessments, their comparative impacts on students' attitudes and science learning outcomes. Four basic questions were asked: What type of science learning stemming from the instruction can best be assessed by the use of traditional paper-and pencil test? What type of science learning stemming from the instruction can best be assessed by the use of alternative assessment? What are the differences in the types of learning outcomes that can be assessed by the use of paper-pencil test and alternative assessment test? Is there a difference in students' attitude towards learning science when assessment of outcomes is by alternative assessment means compared to traditional means compared to traditional means? A mixed methodology involving quantitative and qualitative techniques was utilized. However, the study was essentially a case study. Quantitative data analysis included content achievement and attitude results, to which non-parametric statistics were applied. Analysis of qualitative data was done as a case study utilizing pre-set protocols resulting in a narrative summary style of report. These outcomes were combined in order to produce conclusions. This study revealed that the traditional method yielded more concrete cognitive content learning than did the alternative assessment. The alternative assessment yielded more psychomotor, cooperative learning and critical thinking skills. In both the alternative and the traditional methods the student's attitudes toward science were positive. There was no significant differences favoring either group. The quantitative findings of no statistically significant differences suggest that at a minimum there is no loss in the use of alternative assessment methods, in this instance, performance testing. Adding the results from the qualitative analysis to this suggests (1) that class groups were more satisfied when alternative methods were employed, and (2) that the two assessment methodologies are complementary to each other, and thus should probably be used together to produce maximum benefit.

Fast inner-volume imaging of the lumbar spine with a spatially focused excitation using a 3D-TSE sequence.

PubMed

Riffel, Philipp; Michaely, Henrik J; Morelli, John N; Paul, Dominik; Kannengiesser, Stephan; Schoenberg, Stefan O; Haneder, Stefan

2015-04-01

The purpose of this study was to evaluate the feasibility and technical quality of a zoomed three-dimensional (3D) turbo spin-echo (TSE) sampling perfection with application optimized contrasts using different flip-angle evolutions (SPACE) sequence of the lumbar spine. In this prospective feasibility study, nine volunteers underwent a 3-T magnetic resonance examination of the lumbar spine including 1) a conventional 3D T2-weighted (T2w) SPACE sequence with generalized autocalibrating partially parallel acquisition technique acceleration factor 2 and 2) a zoomed 3D T2w SPACE sequence with a reduced field of view (reduction factor 2). Images were evaluated with regard to image sharpness, signal homogeneity, and the presence of artifacts by two experienced radiologists. For quantitative analysis, signal-to-noise ratio (SNR) values were calculated. Image sharpness of anatomic structures was statistically significantly greater with zoomed SPACE (P < .0001), whereas the signal homogeneity was statistically significantly greater with conventional SPACE (cSPACE; P = .0003). There were no statistically significant differences in extent of artifacts. Acquisition times were 8:20 minutes for cSPACE and 6:30 minutes for zoomed SPACE. Readers 1 and 2 selected zSPACE as the preferred sequence in five of nine cases. In two of nine cases, both sequences were rated as equally preferred by both the readers. SNR values were statistically significantly greater with cSPACE. In comparison to a cSPACE sequences, zoomed SPACE imaging of the lumbar spine provides sharper images in conjunction with a 25% reduction in acquisition time. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

Teenage pregnancy and mental health beyond the postpartum period: a systematic review.

PubMed

Xavier, Chloé; Benoit, Anita; Brown, Hilary K

2018-06-01

Teenage mothers are at increased risk for adverse social outcomes and short-term health problems, but long-term impacts on mental health are poorly understood. The aims of our systematic review were to determine the association between teenage pregnancy and mental health beyond the postpartum period, critically appraise the literature's quality and guide future research. We systematically searched MEDLINE, Embase, PsycINFO, CINAHL, Scopus and Web of Science from inception to June 2017 for peer-reviewed articles written in English or French. Data were collected using a modified Cochrane Data Extraction Form. Study quality was assessed using the Effective Public Health Practice Project critical appraisal tool. Heterogeneity of studies permitted only a qualitative synthesis. Nine quantitative studies comprising the results from analyses of 11 cohorts met our criteria and were rated as strong (n=5), moderate (n=2) or weak (n=2). Three cohorts found a statistically significant association between teenage pregnancy and poor long-term mental health after adjustment, three found a statistically significant association before but not after adjustment and five did not find a statistically significant association. Studies observed varying degrees of attenuation after considering social context. Studies with statistically significant findings tended to comprise earlier cohorts, with outcomes measured at older ages. The association between teenage pregnancy and mental health beyond the postpartum period remains unclear. Future studies should employ age-period-cohort frameworks to disentangle effects of normative patterns and stress accumulation. Social factors are important in determining long-term mental health of teenage mothers and should be prioritised in prevention and intervention strategies. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Novelty or knowledge? A study of using a student response system in non-major biology courses at a community college

NASA Astrophysics Data System (ADS)

Thames, Tasha Herrington

The advancement in technology integration is laying the groundwork of a paradigm shift in the higher education system (Noonoo, 2011). The National Dropout Prevention Center (n.d.) claims that technology offers some of the best opportunities for presenting instruction to engage students in meaningful education, addressing multiple intelligences, and adjusting to students' various learning styles. The purpose of this study was to investigate if implementing clicker technology would have a statistically significant difference on student retention and student achievement, while controlling for learning styles, for students in non-major biology courses who were and were not subjected to the technology. This study also sought to identify if students perceived the use of clickers as beneficial to their learning. A quantitative quasi-experimental research design was utilized to determine the significance of differences in pre/posttest achievement scores between students who participated during the fall semester in 2014. Overall, 118 students (n = 118) voluntarily enrolled in the researcher's fall non-major Biology course at a southern community college. A total of 71 students were assigned to the experimental group who participated in instruction incorporating the ConcepTest Process with clicker technology along with traditional lecture. The remaining 51 students were assigned to the control group who participated in a traditional lecture format with peer instruction embedded. Statistical analysis revealed the experimental clicker courses did have higher posttest scores than the non-clicker control courses, but this was not significant (p >.05). Results also implied that clickers did not statistically help retain students to complete the course. Lastly, the results indicated that there were no significant statistical difference in student's clicker perception scores between the different learning style preferences.

An analysis of science versus pseudoscience

NASA Astrophysics Data System (ADS)

Hooten, James T.

2011-12-01

This quantitative study identified distinctive features in archival datasets commissioned by the National Science Foundation (NSF) for Science and Engineering Indicators reports. The dependent variables included education level, and scores for science fact knowledge, science process knowledge, and pseudoscience beliefs. The dependent variables were aggregated into nine NSF-defined geographic regions and examined for the years 2004 and 2006. The variables were also examined over all years available in the dataset. Descriptive statistics were determined and tests for normality and homogeneity of variances were performed using Statistical Package for the Social Sciences. Analysis of Variance was used to test for statistically significant differences between the nine geographic regions for each of the four dependent variables. Statistical significance of 0.05 was used. Tukey post-hoc analysis was used to compute practical significance of differences between regions. Post-hoc power analysis using G*Power was used to calculate the probability of Type II errors. Tests for correlations across all years of the dependent variables were also performed. Pearson's r was used to indicate the strength of the relationship between the dependent variables. Small to medium differences in science literacy and education level were observed between many of the nine U.S. geographic regions. The most significant differences occurred when the West South Central region was compared to the New England and the Pacific regions. Belief in pseudoscience appeared to be distributed evenly across all U.S. geographic regions. Education level was a strong indicator of science literacy regardless of a respondent's region of residence. Recommendations for further study include more in-depth investigation to uncover the nature of the relationship between education level and belief in pseudoscience.

Association between Insulin Resistance and Cardiovascular Risk Factors in Polycystic Ovary Syndrome Patients.

PubMed

Wanderley, Miriam da Silva; Pereira, Lara Cristina Ribeiro; Santos, Carla Borges; Cunha, Vinícius Santos da; Neves, Mariam Viviane Jovino

2018-04-01

 To analyze the association between the indirect methods of evaluating insulin resistance (IR) and blood pressure, anthropometric and biochemical parameters in a population of polycystic ovary syndrome (PCOS) patients.  Cross-sectional study performed at the Hospital Universitário de Brasília (HUB, in the Portuguese acronym) involving PCOS patients diagnosed from January 2011 to January 2013. Four indirect methods, namely, fasting blood insulin level, fasting glucose/insulin ratio (G/I), homeostatic model-assessment-insulin resistance (HOMA-IR), and the quantitative insulin sensitivity check index (QUICKI), were used to obtain the IR diagnosis. The data were analyzed using the test of proportions, the Chi-square test, and Fisher exact test, when indicated.  Out of the 83 patients assessed, aged 28.79 ± 5.85, IR was found in 51.81-66.2% of them using the G/I ratio and the QUICKI, respectively. The test of proportions did not show a significant difference between the methods analyzed. The proportion of IR diagnoses was statistically higher in obese women than in women with normal body mass index (BMI). We observed a statistically significant association between all the methods for diagnosing IR and BMI, waist circumference (WC) and lipid accumulation product (LAP). With regards to arterial hypertension (AH), we observed a significant association according to three methods, with the exception of the ratio G/I.  Insulin resistance prevalence varied according to the diagnostic method employed, with no statistical difference between them. The proportion of IR diagnoses was statistically higher in obese women than in women with normal BMI. We observed a significant association between IR and WC, BMI, LAP, as well as dyslipidemia and AH in a high proportion of patients. Thieme Revinter Publicações Ltda Rio de Janeiro, Brazil.

Transforming attitudes and lives: Liberating African-American elementary and middle school students in out-of-school time STEM education

NASA Astrophysics Data System (ADS)

Smith, Charisse F.

Statistically, African-Americans, women, and the disabled are underrepresented in the fields of Science, Technology, Engineering, and Math (STEM). Historically, these underrepresented students, are described as being unrecognized and underdeveloped in the American STEM circuit. Many experience deficient and inadequate educational resources, are not encouraged to pursue STEM education and careers, and are confronted with copious obstructions. In this quantitative study, the researcher collected pretest and posttest survey data from a group of 4th, 5th, and 6th-grade African-American students in Title I funded schools. The reseacher used quantitative analysis to determine any significant differences in the science related attitudes between and within groups who participated in Out of School-Time Science, Technology, Engineering, and Mathematics programs and those who did not. Results revealed no significant differences in the science related attitudes between the groups of the students who participated in the Out of School Time-Science, Technology, Engineering, and Mathematics programs and those who did not. Results also revealed no significant differences in the science related attitudes within the groups of students who participated in the Out of School Time-Science, Technology, Engineering, and Mathematics programs and those who did not.

TU-F-CAMPUS-J-05: Effect of Uncorrelated Noise Texture On Computed Tomography Quantitative Image Features

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

Oliver, J; Budzevich, M; Moros, E

Purpose: To investigate the relationship between quantitative image features (i.e. radiomics) and statistical fluctuations (i.e. electronic noise) in clinical Computed Tomography (CT) using the standardized American College of Radiology (ACR) CT accreditation phantom and patient images. Methods: Three levels of uncorrelated Gaussian noise were added to CT images of phantom and patients (20) acquired in static mode and respiratory tracking mode. We calculated the noise-power spectrum (NPS) of the original CT images of the phantom, and of the phantom images with added Gaussian noise with means of 50, 80, and 120 HU. Concurrently, on patient images (original and noise-added images),more » image features were calculated: 14 shape, 19 intensity (1st order statistics from intensity volume histograms), 18 GLCM features (2nd order statistics from grey level co-occurrence matrices) and 11 RLM features (2nd order statistics from run-length matrices). These features provide the underlying structural information of the images. GLCM (size 128x128) was calculated with a step size of 1 voxel in 13 directions and averaged. RLM feature calculation was performed in 13 directions with grey levels binning into 128 levels. Results: Adding the electronic noise to the images modified the quality of the NPS, shifting the noise from mostly correlated to mostly uncorrelated voxels. The dramatic increase in noise texture did not affect image structure/contours significantly for patient images. However, it did affect the image features and textures significantly as demonstrated by GLCM differences. Conclusion: Image features are sensitive to acquisition factors (simulated by adding uncorrelated Gaussian noise). We speculate that image features will be more difficult to detect in the presence of electronic noise (an uncorrelated noise contributor) or, for that matter, any other highly correlated image noise. This work focuses on the effect of electronic, uncorrelated, noise and future work shall examine the influence of changes in quantum noise on the features. J. Oliver was supported by NSF FGLSAMP BD award HRD #1139850 and the McKnight Doctoral Fellowship.« less

MEG Frequency Analysis Depicts the Impaired Neurophysiological Condition of Ischemic Brain

PubMed Central

Ikeda, Hidetoshi; Tsuyuguchi, Naohiro; Uda, Takehiro; Okumura, Eiichi; Asakawa, Takashi; Haruta, Yasuhiro; Nishiyama, Hideki; Okada, Toyoji; Kamada, Hajime; Ohata, Kenji; Miki, Yukio

2016-01-01

Purpose Quantitative imaging of neuromagnetic fields based on automated region of interest (ROI) setting was analyzed to determine the characteristics of cerebral neural activity in ischemic areas. Methods Magnetoencephalography (MEG) was used to evaluate spontaneous neuromagnetic fields in the ischemic areas of 37 patients with unilateral internal carotid artery (ICA) occlusive disease. Voxel-based time-averaged intensity of slow waves was obtained in two frequency bands (0.3–4 Hz and 4–8 Hz) using standardized low-resolution brain electromagnetic tomography (sLORETA) modified for a quantifiable method (sLORETA-qm). ROIs were automatically applied to the anterior cerebral artery (ACA), anterior middle cerebral artery (MCAa), posterior middle cerebral artery (MCAp), and posterior cerebral artery (PCA) using statistical parametric mapping (SPM). Positron emission tomography with 15O-gas inhalation (15O-PET) was also performed to evaluate cerebral blood flow (CBF) and oxygen extraction fraction (OEF). Statistical analyses were performed using laterality index of MEG and 15O-PET in each ROI with respect to distribution and intensity. Results MEG revealed statistically significant laterality in affected MCA regions, including 4–8 Hz waves in MCAa, and 0.3–4 Hz and 4–8 Hz waves in MCAp (95% confidence interval: 0.020–0.190, 0.030–0.207, and 0.034–0.213), respectively. We found that 0.3–4 Hz waves in MCAp were highly correlated with CBF in MCAa and MCAp (r = 0.74, r = 0.68, respectively), whereas 4–8 Hz waves were moderately correlated with CBF in both the MCAa and MCAp (r = 0.60, r = 0.63, respectively). We also found that 4–8 Hz waves in MCAp were statistically significant for misery perfusion identified on 15O-PET (p<0.05). Conclusions Quantitatively imaged spontaneous neuromagnetic fields using the automated ROI setting enabled clear depiction of cerebral ischemic areas. Frequency analysis may reveal unique neural activity that is distributed in the impaired vascular metabolic territory, in which the cerebral infarction has not yet been completed. PMID:27992543

Quantitative imaging biomarkers: a review of statistical methods for computer algorithm comparisons.

PubMed

Obuchowski, Nancy A; Reeves, Anthony P; Huang, Erich P; Wang, Xiao-Feng; Buckler, Andrew J; Kim, Hyun J Grace; Barnhart, Huiman X; Jackson, Edward F; Giger, Maryellen L; Pennello, Gene; Toledano, Alicia Y; Kalpathy-Cramer, Jayashree; Apanasovich, Tatiyana V; Kinahan, Paul E; Myers, Kyle J; Goldgof, Dmitry B; Barboriak, Daniel P; Gillies, Robert J; Schwartz, Lawrence H; Sullivan, Daniel C

2015-02-01

Quantitative biomarkers from medical images are becoming important tools for clinical diagnosis, staging, monitoring, treatment planning, and development of new therapies. While there is a rich history of the development of quantitative imaging biomarker (QIB) techniques, little attention has been paid to the validation and comparison of the computer algorithms that implement the QIB measurements. In this paper we provide a framework for QIB algorithm comparisons. We first review and compare various study designs, including designs with the true value (e.g. phantoms, digital reference images, and zero-change studies), designs with a reference standard (e.g. studies testing equivalence with a reference standard), and designs without a reference standard (e.g. agreement studies and studies of algorithm precision). The statistical methods for comparing QIB algorithms are then presented for various study types using both aggregate and disaggregate approaches. We propose a series of steps for establishing the performance of a QIB algorithm, identify limitations in the current statistical literature, and suggest future directions for research. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

An NGF mimetic, MIM-D3, stimulates conjunctival cell glycoconjugate secretion and demonstrates therapeutic efficacy in a rat model of dry eye.

PubMed

Jain, Pooja; Li, Ruihong; Lama, Teresa; Saragovi, H Uri; Cumberlidge, Garth; Meerovitch, Karen

2011-10-01

The aim of this study was to evaluate the efficacy of MIM-D3, a small molecule nerve growth factor (NGF) peptidomimetic, as a therapeutic agent in rats with scopolamine induced dry eye. NGF plays an important role in ocular surface maintenance and corneal wound healing and was recently shown to have mucin secretagogue activity in conjunctival cells. We investigated whether MIM-D3 increased glycoconjugate secretion in conjunctival cells in vitro and in rat tear fluids in vivo. Primary rat conjunctival cell cultures were treated with increasing concentrations of MIM-D3 and evaluated for glycoconjugate secretion, proliferation and MAPK1/2 activation. Glycoconjugates were quantitated in tear fluids from normal rats treated topically with increasing doses of MIM-D3 (0.4%, 1% and 2.5%). Dry eye was induced in rats by subcutaneous scopolamine treatment, administered by surgically implanted osmotic pumps for 14 or 28 days. Aqueous tear production, tear clearance, fluorescein corneal staining and tear break-up time (tBUT) were evaluated. Glycoconjugates and NGF were quantitated in the tear fluids by enzyme-linked lectin assay (ELLA) and enzyme-linked immunosorbant assay (ELISA), respectively. We found that 50 μM MIM-D3 statistically significantly induced a 1.3-fold increase in glycoconjugate secretion and a 2.3-fold increase in MAPK1/2 activation without increasing proliferation from conjunctival cell cultures. Application of 2.5% MIM-D3 in normal rat eyes statistically significantly increased tear glycoconjugate concentration by 2.3-fold. In the experimental dry eye model, application of 1% MIM-D3 to rat eyes for either 1 or 17 consecutive days, followed by 1 week of no dosing produced a statistically significant decrease in corneal staining (p < 0.001), a slight increase in tBUT, and increases in tear glycoconjugates (p < 0.05) compared to vehicle. Scopolamine treatment also caused a statistically significant increase of endogenous NGF in tears (p < 0.005). We concluded that the increase in glycoconjugate concentration by the 1% MIM-D3 dose may have improved the quality and stability of the tear film, and thereby improved healing on the ocular surface in dry eye. Therefore, MIM-D3 may have therapeutic potential as a topical agent for the treatment of dry eye. Copyright © 2011 Elsevier Ltd. All rights reserved.

Physical and genetic-interaction density reveals functional organization and informs significance cutoffs in genome-wide screens

PubMed Central

Dittmar, John C.; Pierce, Steven; Rothstein, Rodney; Reid, Robert J. D.

2013-01-01

Genome-wide experiments often measure quantitative differences between treated and untreated cells to identify affected strains. For these studies, statistical models are typically used to determine significance cutoffs. We developed a method termed “CLIK” (Cutoff Linked to Interaction Knowledge) that overlays biological knowledge from the interactome on screen results to derive a cutoff. The method takes advantage of the fact that groups of functionally related interacting genes often respond similarly to experimental conditions and, thus, cluster in a ranked list of screen results. We applied CLIK analysis to five screens of the yeast gene disruption library and found that it defined a significance cutoff that differed from traditional statistics. Importantly, verification experiments revealed that the CLIK cutoff correlated with the position in the rank order where the rate of true positives drops off significantly. In addition, the gene sets defined by CLIK analysis often provide further biological perspectives. For example, applying CLIK analysis retrospectively to a screen for cisplatin sensitivity allowed us to identify the importance of the Hrq1 helicase in DNA crosslink repair. Furthermore, we demonstrate the utility of CLIK to determine optimal treatment conditions by analyzing genome-wide screens at multiple rapamycin concentrations. We show that CLIK is an extremely useful tool for evaluating screen quality, determining screen cutoffs, and comparing results between screens. Furthermore, because CLIK uses previously annotated interaction data to determine biologically informed cutoffs, it provides additional insights into screen results, which supplement traditional statistical approaches. PMID:23589890

Predictive value of PD-L1 based on mRNA level in the treatment of stage IV melanoma with ipilimumab.

PubMed

Brüggemann, C; Kirchberger, M C; Goldinger, S M; Weide, B; Konrad, A; Erdmann, M; Schadendorf, D; Croner, R S; Krähenbühl, L; Kähler, K C; Hafner, C; Leisgang, W; Kiesewetter, F; Dummer, R; Schuler, G; Stürzl, M; Heinzerling, L

2017-10-01

PD-L1 is established as a predictive marker for therapy of non-small cell lung cancer with pembrolizumab. Furthermore, PD-L1 positive melanoma has shown more favorable outcomes when treated with anti-PD1 antibodies and dacarbazine compared to PD-L1 negative melanoma. However, the role of PD-L1 expression with regard to response to checkpoint inhibition with anti-CTLA-4 is not clear, yet. In addition, the lack of standardization in the immunohistochemical assessment of PD-L1 makes the comparison of results difficult. In this study, we investigated the PD-L1 gene expression with a new fully automated technique via RT-PCR and correlated the findings with the response to the anti-CTLA-4 antibody ipilimumab. Within a retrospective multi-center trial, PD-L1 gene expression was evaluated in 78 melanoma patients in a total of 111 pre-treatment tumor samples from 6 skin cancer centers and analyzed with regard to response to ipilimumab. For meaningful statistical analysis, the cohort was enriched for responders with 30 responders and 48 non-responders. Gene expression was assessed by quantitative RT-PCR after extracting mRNA from formalin-fixed paraffin embedded tumor tissue and correlated with results from immunohistochemical (IHC) stainings. The evaluation of PD-L1 expression based on mRNA level is feasible. Correlation between PD-L1 expression as assessed by IHC and RT-PCR showed varying levels of concordance depending on the antibody employed. RT-PCR should be further investigated to measure PD-L1 expression, since it is a semi-quantitative method with observer-independent evaluation. With this approach, there was no statistical significant difference in the PD-L1 expression between responders and non-responders to the therapy with ipilimumab. The evaluation of PD-L1 expression based on mRNA level is feasible. Correlation between PD-L1 expression as assessed by IHC and RT-PCR showed varying levels of concordance depending on the antibody employed. RT-PCR should be further investigated to measure PD-L1 expression, since it is a semi-quantitative method with observer-independent evaluation. With this approach, there was no statistical significant difference in the PD-L1 expression between responders and non-responders to the therapy with ipilimumab.

Validation of HPLC and UV spectrophotometric methods for the determination of meropenem in pharmaceutical dosage form.

PubMed

Mendez, Andreas S L; Steppe, Martin; Schapoval, Elfrides E S

2003-12-04

A high-performance liquid chromatographic method and a UV spectrophotometric method for the quantitative determination of meropenem, a highly active carbapenem antibiotic, in powder for injection were developed in present work. The parameters linearity, precision, accuracy, specificity, robustness, limit of detection and limit of quantitation were studied according to International Conference on Harmonization guidelines. Chromatography was carried out by reversed-phase technique on an RP-18 column with a mobile phase composed of 30 mM monobasic phosphate buffer and acetonitrile (90:10; v/v), adjusted to pH 3.0 with orthophosphoric acid. The UV spectrophotometric method was performed at 298 nm. The samples were prepared in water and the stability of meropenem in aqueous solution at 4 and 25 degrees C was studied. The results were satisfactory with good stability after 24 h at 4 degrees C. Statistical analysis by Student's t-test showed no significant difference between the results obtained by the two methods. The proposed methods are highly sensitive, precise and accurate and can be used for the reliable quantitation of meropenem in pharmaceutical dosage form.

Quantitative analysis of the polarization characteristics of atherosclerotic plaques

NASA Astrophysics Data System (ADS)

Gubarkova, Ekaterina V.; Kirillin, Michail Y.; Dudenkova, Varvara V.; Kiseleva, Elena B.; Moiseev, Alexander A.; Gelikonov, Grigory V.; Timofeeva, Lidia B.; Fiks, Ilya I.; Feldchtein, Felix I.; Gladkova, Natalia D.

2016-04-01

In this study we demonstrate the capability of cross-polarization optical coherence tomography (CP OCT) to assess collagen and elastin fibers condition in atherosclerotic plaques basing on ratio of the OCT signal levels in cross- and co- polarizations. We consider the depolarization factor (DF) and the effective birefringence (Δn) as quantitative characteristics of CP OCT images. We revealed that calculation of both DF and Δn in the region of interest (fibrous cap) yields a statistically significant difference between stable and unstable plaques (0.46+/-0.21 vs 0.09+/-0.04 for IDF; (4.7+/-1.0)•10-4 vs (2.5+/-0.7)•10-4 for Δn p<0.05). In parallel with CP OCT we used the nonlinear microscopy for analysis of thin cross-section of atherosclerotic plaque, revealing the different average isotropy index of collagen and elastin fibers for stable and unstable plaques (0.30 +/- 0.10 vs 0.70 +/- 0.08; p<0.001). The proposed approach for quantitative assessment of CP OCT images allows cross-scattering and birefringence characterization of stable and unstable atherosclerotic plaques.

Proteus mirabilis biofilm - qualitative and quantitative colorimetric methods-based evaluation.

PubMed

Kwiecinska-Piróg, Joanna; Bogiel, Tomasz; Skowron, Krzysztof; Wieckowska, Ewa; Gospodarek, Eugenia

2014-01-01

Proteus mirabilis strains ability to form biofilm is a current topic of a number of research worldwide. In this study the biofilm formation of P. mirabilis strains derived from urine of the catheterized and non-catheterized patients has been investigated. A total number of 39 P. mirabilis strains isolated from the urine samples of the patients of dr Antoni Jurasz University Hospital No. 1 in Bydgoszcz clinics between 2011 and 2012 was used. Biofilm formation was evaluated using two independent quantitative and qualitative methods with TTC (2,3,5-triphenyl-tetrazolium chloride) and CV (crystal violet) application. The obtained results confirmed biofilm formation by all the examined strains, except quantitative method with TTC, in which 7.7% of the strains did not have this ability. It was shown that P. mirabilis rods have the ability to form biofilm on the surfaces of both biomaterials applied, polystyrene and polyvinyl chloride (Nelaton catheters). The differences in ability to form biofilm observed between P. mirabilis strains derived from the urine of the catheterized and non-catheterized patients were not statistically significant.

Nanoscale Structure of Type I Collagen Fibrils: Quantitative Measurement of D-spacing

PubMed Central

Erickson, Blake; Fang, Ming; Wallace, Joseph M.; Orr, Bradford G.; Les, Clifford M.; Holl, Mark M. Banaszak

2012-01-01

This paper details a quantitative method to measure the D-periodic spacing of Type I collagen fibrils using Atomic Force Microscopy coupled with analysis using a 2D Fast Fourier Transform approach. Instrument calibration, data sampling and data analysis are all discussed and comparisons of the data to the complementary methods of electron microscopy and X-ray scattering are made. Examples of the application of this new approach to the analysis of Type I collagen morphology in disease models of estrogen depletion and Osteogenesis Imperfecta are provided. We demonstrate that it is the D-spacing distribution, not the D-spacing mean, that showed statistically significant differences in estrogen depletion associated with early stage Osteoporosis and Osteogenesis Imperfecta. The ability to quantitatively characterize nanoscale morphological features of Type I collagen fibrils will provide important structural information regarding Type I collagen in many research areas, including tissue aging and disease, tissue engineering, and gene knock out studies. Furthermore, we also envision potential clinical applications including evaluation of tissue collagen integrity under the impact of diseases or drug treatments. PMID:23027700

Histomorphometric, fractal and lacunarity comparative analysis of sheep (Ovis aries), goat (Capra hircus) and roe deer (Capreolus capreolus) compact bone samples.

PubMed

Gudea, A I; Stefan, A C

2013-08-01

Quantitative and qualitative studies dealing with histomorphometry of the bone tissue play a new role in modern legal medicine/forensic medicine and archaeozoology nowadays. This study deals with the differences found in case of humerus and metapodial bones of recent sheep (Ovis aries), goat (Capra hircus) and roedeer (Capreolus capreolus) specimens, both from a qualitative point of view, but mainly from a quantitative perspective. A novel perspective given by the fractal analysis performed on the digital histological images is approached. This study shows that the qualitative assessment may not be a reliable one due to the close resemblance of the structures. From the quantitative perspective (several measurements performed on osteonal units and statistical processing of data),some of the elements measured show significant differences among 3 species(the primary osteonal diameter, etc.). The fractal analysis and the lacunarity of the images show a great deal of potential, proving that this type of analysis can be of great help in the separation of the material from this perspective.

An Informed Approach to Improving Quantitative Literacy and Mitigating Math Anxiety in Undergraduates Through Introductory Science Courses

NASA Astrophysics Data System (ADS)

Follette, K.; McCarthy, D.

2012-08-01

Current trends in the teaching of high school and college science avoid numerical engagement because nearly all students lack basic arithmetic skills and experience anxiety when encountering numbers. Nevertheless, such skills are essential to science and vital to becoming savvy consumers, citizens capable of recognizing pseudoscience, and discerning interpreters of statistics in ever-present polls, studies, and surveys in which our society is awash. Can a general-education collegiate course motivate students to value numeracy and to improve their quantitative skills in what may well be their final opportunity in formal education? We present a tool to assess whether skills in numeracy/quantitative literacy can be fostered and improved in college students through the vehicle of non-major introductory courses in astronomy. Initial classroom applications define the magnitude of this problem and indicate that significant improvements are possible. Based on these initial results we offer this tool online and hope to collaborate with other educators, both formal and informal, to develop effective mechanisms for encouraging all students to value and improve their skills in basic numeracy.

Organizational structure, team process, and future directions of interprofessional health care teams.

PubMed

Cole, Kenneth D; Waite, Martha S; Nichols, Linda O

2003-01-01

For a nationwide Geriatric Interdisciplinary Team Training (GITT) program evaluation of 8 sites and 26 teams, team evaluators developed a quantitative and qualitative team observation scale (TOS), examining structure, process, and outcome, with specific focus on the training function. Qualitative data provided an important expansion of quantitative data, highlighting positive effects that were not statistically significant, such as role modeling and training occurring within the clinical team. Qualitative data could also identify "too much" of a coded variable, such as time spent in individual team members' assessments and treatment plans. As healthcare organizations have increasing demands for productivity and changing reimbursement, traditional models of teamwork, with large teams and structured meetings, may no longer be as functional as they once were. To meet these constraints and to train students in teamwork, teams of the future will have to make choices, from developing and setting specific models to increasing the use of information technology to create virtual teams. Both quantitative and qualitative data will be needed to evaluate these new types of teams and the important outcomes they produce.

Mental health benefits of interactions with nature in children and teenagers: a systematic review.

PubMed

Tillmann, Suzanne; Tobin, Danielle; Avison, William; Gilliland, Jason

2018-06-27

It is commonly believed that nature has positive impacts on children's health, including physical, mental and social dimensions. This review focuses on how accessibility to, exposure to and engagement with nature affects the mental health of children and teenagers. Ten academic databases were used to systematically search and identify primary research papers in English or French from 1990 to 1 March 2017. Papers were included for review based on their incorporation of nature, children and teenagers (0-18 years), quantitative results and focus on mental health. Of the 35 papers included in the review, the majority focused on emotional well-being and attention deficit disorder/hyperactivity disorder. Other outcome measures included overall mental health, self-esteem, stress, resilience, depression and health-related quality of life. About half of all reported findings revealed statistically significant positive relationships between nature and mental health outcomes and almost half reported no statistical significance. Findings support the contention that nature positively influences mental health; however, in most cases, additional research with more rigorous study designs and objective measures of both nature and mental health outcomes are needed to confirm statistically significant relationships. Existing evidence is limited by the cross-sectional nature of most papers. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Demineralization of resin-sealed enamel by soft drinks in a clinically relevant pH cycling model.

PubMed

Bartels, Agata A; Evans, Carla A; Viana, Grace; Bedran-Russo, Ana K

2016-04-01

To compare the in vitro protective effect of orthodontic sealants on the enamel demineralization under a soft drink-induced erosive challenge. The facial surfaces of bovine incisors were sectioned into 5 mm x 4 mm x 4 mm enamel blocks. Specimens were randomly assigned to three surface protection measures: control (exposed enamel), coating with Transbond XT (unfilled resin primer), or coating with Opal Seal (filled and fluoride releasing primer). Thermocycling was used to simulate aging. The specimens were pH cycled through an acidic buffer, test beverage and a neutral buffer for a total of 7 days. Test beverages included water, Diet Mountain Dew, and Coke Classic. Quantitative light-induced fluorescence (QLF) images were taken at baseline and after aging. Final QLF images were taken to evaluate the demineralization of enamel. Data were analyzed statistically using a two-way ANOVA to compare the interaction between enamel surface protection and beverages as well as one-way ANOVA to compare surface protection and the test beverage levels. A statistically significant interaction was found between the surface protected groups and the test beverage groups (P < 0.05). Statistically significant differences were found among the test beverage groups (P < 0.05) and among the surface protection groups (P < 0.05). Coke Classic went through the sealant layer resulting in high enamel demineralization. Enamel coating with Opal Seal significantly reduced the erosive attack of beverages.

Quantitation of flavonoid constituents in citrus fruits.

PubMed

Kawaii, S; Tomono, Y; Katase, E; Ogawa, K; Yano, M

1999-09-01

Twenty-four flavonoids have been determined in 66 Citrus species and near-citrus relatives, grown in the same field and year, by means of reversed phase high-performance liquid chromatography analysis. Statistical methods have been applied to find relations among the species. The F ratios of 21 flavonoids obtained by applying ANOVA analysis are significant, indicating that a classification of the species using these variables is reasonable to pursue. Principal component analysis revealed that the distributions of Citrus species belonging to different classes were largely in accordance with Tanaka's classification system.

Long- and short-time analysis of heartbeat sequences: correlation with mortality risk in congestive heart failure patients.

PubMed

Allegrini, P; Balocchi, R; Chillemi, S; Grigolini, P; Hamilton, P; Maestri, R; Palatella, L; Raffaelli, G

2003-06-01

We analyze RR heartbeat sequences with a dynamic model that satisfactorily reproduces both the long- and the short-time statistical properties of heart beating. These properties are expressed quantitatively by means of two significant parameters, the scaling delta concerning the asymptotic effects of long-range correlation, and the quantity 1-pi establishing the amount of uncorrelated fluctuations. We find a correlation between the position in the phase space (delta, pi) of patients with congestive heart failure and their mortality risk.

A quantitative comparison of corrective and perfective maintenance

NASA Technical Reports Server (NTRS)

Henry, Joel; Cain, James

1994-01-01

This paper presents a quantitative comparison of corrective and perfective software maintenance activities. The comparison utilizes basic data collected throughout the maintenance process. The data collected are extensive and allow the impact of both types of maintenance to be quantitatively evaluated and compared. Basic statistical techniques test relationships between and among process and product data. The results show interesting similarities and important differences in both process and product characteristics.

Quantitative assessment of Naegleria fowleri and fecal indicator bacteria in brackish water of Lake Pontchartrain, Louisiana.

PubMed

Xue, Jia; Lamar, Frederica G; Zhang, Bowen; Lin, Siyu; Lamori, Jennifer G; Sherchan, Samendra P

2018-05-01

Brackish water samples from Lake Pontchartrain in Louisiana were assessed for the presence of pathogenic amoeba Naegleria fowleri, which causes primary amoebic meningoencephalitis (PAM). In our study, quantitative polymerase chain reaction (qPCR) methods were used to determine N. fowleri, E. coli, and enterococci in water collected from Lake Pontchartrain. N. fowleri target sequence was detected in 35.4% (56/158) of the water samples from ten sites around the lake. Statistically significant positive correlations between N. fowleri concentration and water temperature as well as E. coli (qPCR) were observed. Multiple linear regression (MLR) model shows seasonal factor (summer or winter) has significant effect on the concentration of N. fowleri, E. coli and enterococci (qPCR) concentration. Significant positive relationships between E. coli and enterococci was observed from both qPCR (r=0.25) and culture based method (r=0.54). Meanwhile, significant positive correlation between qPCR and culture based methods for enterococci concentration was observed (r=0.33). In our study, water temperature and E. coli concentration were indicative of N. fowleri concentrations in brackish water environment. Future research is needed to determine whether sediment is a source of N. fowleri found in the water column. Copyright © 2017 Elsevier B.V. All rights reserved.

Low socioeconomic status is associated with worse survival in children with cancer: a systematic review.

PubMed

Gupta, Sumit; Wilejto, Marta; Pole, Jason D; Guttmann, Astrid; Sung, Lillian

2014-01-01

While low socioeconomic status (SES) has been associated with inferior cancer outcome among adults, its impact in pediatric oncology is unclear. Our objective was therefore to conduct a systematic review to determine the impact of SES upon outcome in children with cancer. We searched Ovid Medline, EMBASE and CINAHL from inception to December 2012. Studies for which survival-related outcomes were reported by socioeconomic subgroups were eligible for inclusion. Two reviewers independently assessed articles and extracted data. Given anticipated heterogeneity, no quantitative meta-analyses were planned a priori. Of 7,737 publications, 527 in ten languages met criteria for full review; 36 studies met final inclusion criteria. In low- and middle-income countries (LMIC), lower SES was uniformly associated with inferior survival, regardless of the measure chosen. The majority of associations were statistically significant. Of 52 associations between socioeconomic variables and outcome among high-income country (HIC) children, 38 (73.1%) found low SES to be associated with worse survival, 15 of which were statistically significant. Of the remaining 14 (no association or high SES associated with worse survival), only one was statistically significant. Both HIC studies examining the effect of insurance found uninsured status to be statistically associated with inferior survival. Socioeconomic gradients in which low SES is associated with inferior childhood cancer survival are ubiquitous in LMIC and common in HIC. Future studies should elucidate mechanisms underlying these gradients, allowing the design of interventions mediating socioeconomic effects. Targeting the effect of low SES will allow for further improvements in childhood cancer survival.

Carbon and nitrogen isotopic signatures and nitrogen profile to identify adulteration in organic fertilizers.

PubMed

Verenitch, Sergei; Mazumder, Asit

2012-08-29

Recently it has been shown that stable isotopes of nitrogen can be used to discriminate between organic and synthetic fertilizers, but the robustness of the approach is questionable. This work developed a comprehensive method that is far more robust in identifying an adulteration of organic nitrogen fertilizers. Organic fertilizers of various types (manures, composts, blood meal, bone meal, fish meal, products of poultry and plant productions, molasses and seaweed based, and others) available on the North American market were analyzed to reveal the most sensitive criteria as well as their quantitative ranges, which can be used in their authentication. Organic nitrogen fertilizers of known origins with a wide δ(15)N range between -0.55 and 28.85‰ (n = 1258) were characterized for C and N content, δ(13)C, δ(15)N, viscosity, pH, and nitrogen profile (urea, ammonia, organic N, water insoluble N, and NO3). A statistically significant data set of characterized unique organic nitrogen fertilizers (n = 335) of various known origins has been assembled. Deliberately adulterated samples of different types of organic fertilizers mixed with synthetic fertilizers at a wide range of proportions have been used to develop the quantitative critical characteristics of organic fertilizers as the key indicators of their adulteration. Statistical analysis based on the discriminant functions of the quantitative critical characteristics of organic nitrogen fertilizers from 14 different source materials revealed a very high average rate of correct classification. The developed methodology has been successfully used as a source identification tool for numerous commercial nitrogen fertilizers available on the North American market.

Some Epistemological Considerations Concerning Quantitative Analysis

ERIC Educational Resources Information Center

Dobrescu, Emilian

2008-01-01

This article presents the author's address at the 2007 "Journal of Applied Quantitative Methods" ("JAQM") prize awarding festivity. The festivity was included in the opening of the 4th International Conference on Applied Statistics, November 22, 2008, Bucharest, Romania. In the address, the author reflects on three theses that…

Quantitative Graphics in Newspapers.

ERIC Educational Resources Information Center

Tankard, James W., Jr.

The use of quantitative graphics in newspapers requires achieving a balance between being accurate and getting the attention of the reader. The statistical representations in newspapers are drawn by graphic designers whose key technique is fusion--the striking combination of two visual images. This technique often results in visual puns,…

78 FR 48681 - Proposed Data Collections Submitted for Public Comment and Recommendations

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-09

.... Qualitative and quantitative data will be collected through progress reports, surveys, the health impact tracking tool, and interviews. Quantitative data will be analyzed using descriptive statistics. Qualitative... States (SOTS) online surveys, (3) Interviews, and (4) Online surveys related to the Regional Network...

76 FR 74802 - Agency Information Collection Activities: Proposed Collection; Comment Request; Generic Clearance...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-01

.... Currie, Program Analyst, Office of policy for Extramural Research Administration, 6705 Rockledge Drive... perceptions and opinions, but are not statistical surveys that yield quantitative results that can be... generic clearance for qualitative information will not be used for quantitative information collections...

Statistical Parametric Mapping to Identify Differences between Consensus-Based Joint Patterns during Gait in Children with Cerebral Palsy.

PubMed

Nieuwenhuys, Angela; Papageorgiou, Eirini; Desloovere, Kaat; Molenaers, Guy; De Laet, Tinne

2017-01-01

Experts recently identified 49 joint motion patterns in children with cerebral palsy during a Delphi consensus study. Pattern definitions were therefore the result of subjective expert opinion. The present study aims to provide objective, quantitative data supporting the identification of these consensus-based patterns. To do so, statistical parametric mapping was used to compare the mean kinematic waveforms of 154 trials of typically developing children (n = 56) to the mean kinematic waveforms of 1719 trials of children with cerebral palsy (n = 356), which were classified following the classification rules of the Delphi study. Three hypotheses stated that: (a) joint motion patterns with 'no or minor gait deviations' (n = 11 patterns) do not differ significantly from the gait pattern of typically developing children; (b) all other pathological joint motion patterns (n = 38 patterns) differ from typically developing gait and the locations of difference within the gait cycle, highlighted by statistical parametric mapping, concur with the consensus-based classification rules. (c) all joint motion patterns at the level of each joint (n = 49 patterns) differ from each other during at least one phase of the gait cycle. Results showed that: (a) ten patterns with 'no or minor gait deviations' differed somewhat unexpectedly from typically developing gait, but these differences were generally small (≤3°); (b) all other joint motion patterns (n = 38) differed from typically developing gait and the significant locations within the gait cycle that were indicated by the statistical analyses, coincided well with the classification rules; (c) joint motion patterns at the level of each joint significantly differed from each other, apart from two sagittal plane pelvic patterns. In addition to these results, for several joints, statistical analyses indicated other significant areas during the gait cycle that were not included in the pattern definitions of the consensus study. Based on these findings, suggestions to improve pattern definitions were made.

Statistical Parametric Mapping to Identify Differences between Consensus-Based Joint Patterns during Gait in Children with Cerebral Palsy

PubMed Central

Papageorgiou, Eirini; Desloovere, Kaat; Molenaers, Guy; De Laet, Tinne

2017-01-01

Experts recently identified 49 joint motion patterns in children with cerebral palsy during a Delphi consensus study. Pattern definitions were therefore the result of subjective expert opinion. The present study aims to provide objective, quantitative data supporting the identification of these consensus-based patterns. To do so, statistical parametric mapping was used to compare the mean kinematic waveforms of 154 trials of typically developing children (n = 56) to the mean kinematic waveforms of 1719 trials of children with cerebral palsy (n = 356), which were classified following the classification rules of the Delphi study. Three hypotheses stated that: (a) joint motion patterns with ‘no or minor gait deviations’ (n = 11 patterns) do not differ significantly from the gait pattern of typically developing children; (b) all other pathological joint motion patterns (n = 38 patterns) differ from typically developing gait and the locations of difference within the gait cycle, highlighted by statistical parametric mapping, concur with the consensus-based classification rules. (c) all joint motion patterns at the level of each joint (n = 49 patterns) differ from each other during at least one phase of the gait cycle. Results showed that: (a) ten patterns with ‘no or minor gait deviations’ differed somewhat unexpectedly from typically developing gait, but these differences were generally small (≤3°); (b) all other joint motion patterns (n = 38) differed from typically developing gait and the significant locations within the gait cycle that were indicated by the statistical analyses, coincided well with the classification rules; (c) joint motion patterns at the level of each joint significantly differed from each other, apart from two sagittal plane pelvic patterns. In addition to these results, for several joints, statistical analyses indicated other significant areas during the gait cycle that were not included in the pattern definitions of the consensus study. Based on these findings, suggestions to improve pattern definitions were made. PMID:28081229

MetaboLyzer: A Novel Statistical Workflow for Analyzing Post-Processed LC/MS Metabolomics Data

PubMed Central

Mak, Tytus D.; Laiakis, Evagelia C.; Goudarzi, Maryam; Fornace, Albert J.

2014-01-01

Metabolomics, the global study of small molecules in a particular system, has in the last few years risen to become a primary –omics platform for the study of metabolic processes. With the ever-increasing pool of quantitative data yielded from metabolomic research, specialized methods and tools with which to analyze and extract meaningful conclusions from these data are becoming more and more crucial. Furthermore, the depth of knowledge and expertise required to undertake a metabolomics oriented study is a daunting obstacle to investigators new to the field. As such, we have created a new statistical analysis workflow, MetaboLyzer, which aims to both simplify analysis for investigators new to metabolomics, as well as provide experienced investigators the flexibility to conduct sophisticated analysis. MetaboLyzer’s workflow is specifically tailored to the unique characteristics and idiosyncrasies of postprocessed liquid chromatography/mass spectrometry (LC/MS) based metabolomic datasets. It utilizes a wide gamut of statistical tests, procedures, and methodologies that belong to classical biostatistics, as well as several novel statistical techniques that we have developed specifically for metabolomics data. Furthermore, MetaboLyzer conducts rapid putative ion identification and putative biologically relevant analysis via incorporation of four major small molecule databases: KEGG, HMDB, Lipid Maps, and BioCyc. MetaboLyzer incorporates these aspects into a comprehensive workflow that outputs easy to understand statistically significant and potentially biologically relevant information in the form of heatmaps, volcano plots, 3D visualization plots, correlation maps, and metabolic pathway hit histograms. For demonstration purposes, a urine metabolomics data set from a previously reported radiobiology study in which samples were collected from mice exposed to gamma radiation was analyzed. MetaboLyzer was able to identify 243 statistically significant ions out of a total of 1942. Numerous putative metabolites and pathways were found to be biologically significant from the putative ion identification workflow. PMID:24266674

Influence of pregnancy on bone density: a risk factor for osteoporosis? Measurements of the calcaneus by ultrasonometry.

PubMed

Kraemer, Bernhard; Schneider, Silke; Rothmund, Ralf; Fehm, Tanja; Wallwiener, Diethelm; Solomayer, Erich-Franz

2012-04-01

There are conflicting opinions in the literature about whether pregnancy influences maternal bone density or osteoporosis development. The study aim was to investigate whether there is a significant alteration in maternal bone density during normal pregnancy. Bone mass of 200 pregnant women aged 22-42 years was measured twice with quantitative ultrasonometry (QUS) of the heel (Os calcaneum). The first measurement was performed between the 10th and 22nd week of pregnancy, follow-up of 149 women took place 0-9 days postpartum. A questionnaire focusing on data affecting bone metabolism and bone turnover was handed out at the first visit. Median reduction in speed of sound (SOS) was 11 m/s at follow-up indicating a decline of the stiffness during pregnancy. No significant correlation was found between lactation period and the obtained values for stiffness, SOS, T score and Z score. For broadband ultrasonographic attenuation, there was a statistically significant difference (p < 0.05) between women who had and had not breastfed. Parameters from patients with a family history of osteoporosis (n = 30) compared to patients without did not reveal statistical significance during pregnancy. Glucocorticoid therapy, nicotine consumption, physical exercise and nutrition was not statistically significant (p > 0.05). SOS value of women with a twin pregnancy was different over the study period (p < 0.05). A reduction in bone mass is possible during pregnancy. Routine evaluation of the bone density in all pregnant women does not seem to be justified; however, it is reasonable in women who present with risk factors. These women could be screened with QUS.

An Integrated MRI and MRS Approach to Evaluation of Multiple Sclerosis with Cognitive Impairment

NASA Astrophysics Data System (ADS)

Liang, Zhengrong; Li, Lihong; Lu, Hongbing; Huang, Wei; Tudorica, Alina; Krupp, Lauren

Magnetic resonance imaging and spectroscopy (MRI/MRS) plays a unique role in multiple sclerosis (MS) evaluation, because of its ability to provide both high image contrast and significant chemical change among brain tissues. The image contrast renders the possibility of quantifying the tissue volumetric and texture variations, e.g., cerebral atrophy and progressing speed, reflecting the ongoing destructive pathologic processes. Any chemical change reflects an early sign of pathological alteration, e.g., decreased N-acetyl aspartate (NAA) in lesions and normal appearing white matter, related to axonal damage or dysfunction. Both MRI and MRS encounter partial volume (PV) effect, which compromises the quantitative capability, especially for MRS. This work aims to develop a statistical framework to segment the tissue mixtures inside each image element, eliminating theoretically the PV effect, and apply the framework to the evaluation of MS with cognitive impairment. The quantitative measures from MRI/MRS neuroimaging are strongly correlated with the qualitative neuropsychological scores of Brief Repeatable Battery (BRB) test on cognitive impairment, demonstrating the usefulness of the PV image segmentation framework in this clinically significant problem.

Quantitative Aspects of Single Molecule Microscopy

PubMed Central

Ober, Raimund J.; Tahmasbi, Amir; Ram, Sripad; Lin, Zhiping; Ward, E. Sally

2015-01-01

Single molecule microscopy is a relatively new optical microscopy technique that allows the detection of individual molecules such as proteins in a cellular context. This technique has generated significant interest among biologists, biophysicists and biochemists, as it holds the promise to provide novel insights into subcellular processes and structures that otherwise cannot be gained through traditional experimental approaches. Single molecule experiments place stringent demands on experimental and algorithmic tools due to the low signal levels and the presence of significant extraneous noise sources. Consequently, this has necessitated the use of advanced statistical signal and image processing techniques for the design and analysis of single molecule experiments. In this tutorial paper, we provide an overview of single molecule microscopy from early works to current applications and challenges. Specific emphasis will be on the quantitative aspects of this imaging modality, in particular single molecule localization and resolvability, which will be discussed from an information theoretic perspective. We review the stochastic framework for image formation, different types of estimation techniques and expressions for the Fisher information matrix. We also discuss several open problems in the field that demand highly non-trivial signal processing algorithms. PMID:26167102

Robot-assisted gait training versus treadmill training in patients with Parkinson’s disease: a kinematic evaluation with gait profile score

PubMed Central

Galli, Manuela; Cimolin, Veronica; De Pandis, Maria Francesca; Le Pera, Domenica; Sova, Ivan; Albertini, Giorgio; Stocchi, Fabrizio; Franceschini, Marco

2016-01-01

Summary The purpose of this study was to quantitatively compare the effects, on walking performance, of end-effector robotic rehabilitation locomotor training versus intensive training with a treadmill in Parkinson’s disease (PD). Fifty patients with PD were randomly divided into two groups: 25 were assigned to the robot-assisted therapy group (RG) and 25 to the intensive treadmill therapy group (IG). They were evaluated with clinical examination and 3D quantitative gait analysis [gait profile score (GPS) and its constituent gait variable scores (GVSs) were calculated from gait analysis data] at the beginning (T0) and at the end (T1) of the treatment. In the RG no differences were found in the GPS, but there were significant improvements in some GVSs (Pelvic Obl and Hip Ab-Add). The IG showed no statistically significant changes in either GPS or GVSs. The end-effector robotic rehabilitation locomotor training improved gait kinematics and seems to be effective for rehabilitation in patients with mild PD. PMID:27678210

Increasing Confidence in a Statistics Course: Assessing Students' Beliefs and Using the Data to Design Curriculum with Students

ERIC Educational Resources Information Center

Huchting, Karen

2013-01-01

Students were involved in the curriculum design of a statistics course. They completed a pre-assessment of their confidence and skills using quantitative methods and statistics. Scores were aggregated, and anonymous data were shown on the first night of class. Using these data, the course was designed, demonstrating evidence-based instructional…

Can't Count or Won't Count? Embedding Quantitative Methods in Substantive Sociology Curricula: A Quasi-Experiment.

PubMed

Williams, Malcolm; Sloan, Luke; Cheung, Sin Yi; Sutton, Carole; Stevens, Sebastian; Runham, Libby

2016-06-01

This paper reports on a quasi-experiment in which quantitative methods (QM) are embedded within a substantive sociology module. Through measuring student attitudes before and after the intervention alongside control group comparisons, we illustrate the impact that embedding has on the student experience. Our findings are complex and even contradictory. Whilst the experimental group were less likely to be distrustful of statistics and appreciate how QM inform social research, they were also less confident about their statistical abilities, suggesting that through 'doing' quantitative sociology the experimental group are exposed to the intricacies of method and their optimism about their own abilities is challenged. We conclude that embedding QM in a single substantive module is not a 'magic bullet' and that a wider programme of content and assessment diversification across the curriculum is preferential.

Meta- and statistical analysis of single-case intervention research data: quantitative gifts and a wish list.

PubMed

Kratochwill, Thomas R; Levin, Joel R

2014-04-01

In this commentary, we add to the spirit of the articles appearing in the special series devoted to meta- and statistical analysis of single-case intervention-design data. Following a brief discussion of historical factors leading to our initial involvement in statistical analysis of such data, we discuss: (a) the value added by including statistical-analysis recommendations in the What Works Clearinghouse Standards for single-case intervention designs; (b) the importance of visual analysis in single-case intervention research, along with the distinctive role that could be played by single-case effect-size measures; and (c) the elevated internal validity and statistical-conclusion validity afforded by the incorporation of various forms of randomization into basic single-case design structures. For the future, we envision more widespread application of quantitative analyses, as critical adjuncts to visual analysis, in both primary single-case intervention research studies and literature reviews in the behavioral, educational, and health sciences. Copyright © 2014 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

A quantitative comparative analysis of Advancement via Independent Determination (AVID) in Texas middle schools

NASA Astrophysics Data System (ADS)

Reed, Krystal Astra

The "Advancement via Individual Determination (AVID) program was designed to provide resources and strategies that enable underrepresented minority students to attend 4-year colleges" (AVID Center, 2013, p. 2). These students are characterized as the forgotten middle in that they have high test scores, average-to-low grades, minority or low socioeconomic status, and will be first-generation college students (AVID, 2011). Research indicates (Huerta, Watt, & Butcher, 2013) that strict adherence to 11 program components supports success of students enrolled in AVID, and AVID certification depends on districts following those components. Several studies (AVID Center, 2013) have investigated claims about the AVID program through qualitative analyses; however, very few have addressed this program quantitatively. This researcher sought to determine whether differences existed between student achievement and attendance rates between AVID and non-AVID middle schools. To achieve this goal, the researcher compared eighth-grade science and seventh- and eighth-grade mathematics scores from the 2007 to 2011 Texas Assessment of Knowledge and Skills (TAKS) and overall attendance rates in demographically equivalent AVID and non-AVID middle schools. Academic Excellence Indicator System (AEIS) reports from the Texas Education Agency (TEA) were used to obtain 2007 to 2011 TAKS results and attendance information for the selected schools. The results indicated a statistically significant difference between AVID demonstration students and non-AVID students in schools with similar CI. No statistically significant differences were found on any component of the TAKS for AVID economically disadvantaged students. The mean scores indicated an achievement gap between non-AVID and AVID demonstration middle schools. The findings from the other three research questions indicated no statistically significant differences between AVID and non-AVID student passing rates on the seventh- and eighth-grade TAKS math tests or on overall attendance rates. The mean scores on the eighth-grade TAKS science test revealed some positive results in the academic performance of economically disadvantaged in non-AVID demonstration middle schools. Specifically, the results indicated that the mean passing percentage of AVID demonstration was lower than that of non-AVID middle schools. The TAKS scores showed a small achievement gap between non-AVID and AVID demonstration middle schools.

Quantitation of heteroplasmy of mtDNA sequence variants identified in a population of AD patients and controls by array-based resequencing.

PubMed

Coon, Keith D; Valla, Jon; Szelinger, Szabolics; Schneider, Lonnie E; Niedzielko, Tracy L; Brown, Kevin M; Pearson, John V; Halperin, Rebecca; Dunckley, Travis; Papassotiropoulos, Andreas; Caselli, Richard J; Reiman, Eric M; Stephan, Dietrich A

2006-08-01

The role of mitochondrial dysfunction in the pathogenesis of Alzheimer's disease (AD) has been well documented. Though evidence for the role of mitochondria in AD seems incontrovertible, the impact of mitochondrial DNA (mtDNA) mutations in AD etiology remains controversial. Though mutations in mitochondrially encoded genes have repeatedly been implicated in the pathogenesis of AD, many of these studies have been plagued by lack of replication as well as potential contamination of nuclear-encoded mitochondrial pseudogenes. To assess the role of mtDNA mutations in the pathogenesis of AD, while avoiding the pitfalls of nuclear-encoded mitochondrial pseudogenes encountered in previous investigations and showcasing the benefits of a novel resequencing technology, we sequenced the entire coding region (15,452 bp) of mtDNA from 19 extremely well-characterized AD patients and 18 age-matched, unaffected controls utilizing a new, reliable, high-throughput array-based resequencing technique, the Human MitoChip. High-throughput, array-based DNA resequencing of the entire mtDNA coding region from platelets of 37 subjects revealed the presence of 208 loci displaying a total of 917 sequence variants. There were no statistically significant differences in overall mutational burden between cases and controls, however, 265 independent sites of statistically significant change between cases and controls were identified. Changed sites were found in genes associated with complexes I (30.2%), III (3.0%), IV (33.2%), and V (9.1%) as well as tRNA (10.6%) and rRNA (14.0%). Despite their statistical significance, the subtle nature of the observed changes makes it difficult to determine whether they represent true functional variants involved in AD etiology or merely naturally occurring dissimilarity. Regardless, this study demonstrates the tremendous value of this novel mtDNA resequencing platform, which avoids the pitfalls of erroneously amplifying nuclear-encoded mtDNA pseudogenes, and our proposed analysis paradigm, which utilizes the availability of raw signal intensity values for each of the four potential alleles to facilitate quantitative estimates of mtDNA heteroplasmy. This information provides a potential new target for burgeoning diagnostics and therapeutics that could truly assist those suffering from this devastating disorder.