Sample records for factor analysis pfa

  1. PFA toolbox: a MATLAB tool for Metabolic Flux Analysis.

    PubMed

    Morales, Yeimy; Bosque, Gabriel; Vehí, Josep; Picó, Jesús; Llaneras, Francisco

    2016-07-11

    Metabolic Flux Analysis (MFA) is a methodology that has been successfully applied to estimate metabolic fluxes in living cells. However, traditional frameworks based on this approach have some limitations, particularly when measurements are scarce and imprecise. This is very common in industrial environments. The PFA Toolbox can be used to face those scenarios. Here we present the PFA (Possibilistic Flux Analysis) Toolbox for MATLAB, which simplifies the use of Interval and Possibilistic Metabolic Flux Analysis. The main features of the PFA Toolbox are the following: (a) It provides reliable MFA estimations in scenarios where only a few fluxes can be measured or those available are imprecise. (b) It provides tools to easily plot the results as interval estimates or flux distributions. (c) It is composed of simple functions that MATLAB users can apply in flexible ways. (d) It includes a Graphical User Interface (GUI), which provides a visual representation of the measurements and their uncertainty. (e) It can use stoichiometric models in COBRA format. In addition, the PFA Toolbox includes a User's Guide with a thorough description of its functions and several examples. The PFA Toolbox for MATLAB is a freely available Toolbox that is able to perform Interval and Possibilistic MFA estimations.

  2. Phylogenetic Factor Analysis.

    PubMed

    Tolkoff, Max R; Alfaro, Michael E; Baele, Guy; Lemey, Philippe; Suchard, Marc A

    2018-05-01

    Phylogenetic comparative methods explore the relationships between quantitative traits adjusting for shared evolutionary history. This adjustment often occurs through a Brownian diffusion process along the branches of the phylogeny that generates model residuals or the traits themselves. For high-dimensional traits, inferring all pair-wise correlations within the multivariate diffusion is limiting. To circumvent this problem, we propose phylogenetic factor analysis (PFA) that assumes a small unknown number of independent evolutionary factors arise along the phylogeny and these factors generate clusters of dependent traits. Set in a Bayesian framework, PFA provides measures of uncertainty on the factor number and groupings, combines both continuous and discrete traits, integrates over missing measurements and incorporates phylogenetic uncertainty with the help of molecular sequences. We develop Gibbs samplers based on dynamic programming to estimate the PFA posterior distribution, over 3-fold faster than for multivariate diffusion and a further order-of-magnitude more efficiently in the presence of latent traits. We further propose a novel marginal likelihood estimator for previously impractical models with discrete data and find that PFA also provides a better fit than multivariate diffusion in evolutionary questions in columbine flower development, placental reproduction transitions and triggerfish fin morphometry.

  3. Potential supplementary utility of combined PFA-100 and functional von Willebrand factor testing for the laboratory assessment of desmopressin and factor concentrate therapy in von Willebrand disease.

    PubMed

    Favaloro, Emmanuel J; Thom, Jim; Patterson, David; Just, Sarah; Baccala, Maria; Dixon, Tracy; Meiring, Muriel; Koutts, Jerry; Rowell, John; Baker, Ross

    2009-09-01

    We performed a retrospective audit of cross-laboratory testing of desmopressin and factor concentrate therapy to assess the potential utility of supplementary testing using the PFA-100 with functional von Willebrand factor (VWF) activity testing. Data were evaluated for a large number of patients with von Willebrand disease of type 1, type 2A or type 2M, as well as a comparative subset of individuals with haemophilia or carriers of haemophilia. Laboratory testing comprised pre and postdesmopressin, or pre and postconcentrate, evaluation of factor VIII, VWF antigen (VWF:Ag) and VWF ristocetin cofactor activity as traditionally performed, supplemented with collagen-binding (VWF:CB) testing and PFA-100 closure times. In brief, both therapies tended to normalize VWF test parameters and closure times in individuals with type 1 von Willebrand disease, with the level of correction in closure times related to the level of normalization of VWF, particularly the VWF:CB. However, although occasional correction of closure times was observed in patients with type 2A or type 2M von Willebrand disease, these did not in general normalize PFA-100 closure times either with desmopressin or factor concentrate therapy. In these patients, improvement in closure times was more likely in those in whom VWF:CB values normalized or when VWF:CB/VWF:Ag ratios normalized. This study confirms that there is a strong relationship between the presenting levels of plasma VWF and PFA-100 closure times, and that the supplementary combination of PFA-100 and VWF:CB testing might provide added clinical utility to current broadly applied testing strategies limited primarily to VWF:Ag, VWF ristocetin cofactor and factor VIII:coagulant. Future prospective investigations are warranted to validate these relationships and to investigate their therapeutic implications.

  4. Von Willebrand factor antigen predicts response to double dose of aspirin and clopidogrel by PFA-100 in patients undergoing primary angioplasty for ST elevation myocardial infarction.

    PubMed

    Gianetti, Jacopo; Parri, Maria Serena; Della Pina, Francesca; Marchi, Federica; Koni, Endrin; De Caterina, Alberto; Maffei, Stefano; Berti, Sergio

    2013-01-01

    Von Willebrand factor (VWF) is an emerging risk factor in acute coronary syndromes. Platelet Function Analyzer (PFA-100) with Collagen/Epinephrine (CEPI) is sensitive to functional alterations of VWF and also identifies patients with high on-treatment platelet reactivity (HPR). The objective of this study was to verify the effect of double dose (DD) of aspirin and clopidogrel on HPR detected by PFA-100 and its relation to VWF and to its regulatory metalloprotease ADAMTS-13. Between 2009 and 2011 we enrolled 116 consecutive patients with ST elevation myocardial infarction undergoing primary PCI with HPR at day 5 after PCI. Patients recruited were then randomized between a standard dose (SD, n = 58) or DD of aspirin and clopidogrel (DD, n = 58), maintained for 6 months follow-up. Blood samples for PFA-100, light transmittance aggregometry, and VWF/ADAMTS-13 analysis were collected after 5, 30, and 180 days (Times 0, 1, and 2). At Times 1 and 2 we observed a significantly higher CEPI closure times (CT) in DD as compared to SD (P < 0.001). Delta of CEPI-CT (T1 - T0) was significantly related to VWF (P < 0.001) and inversely related to ADAMTS-13 (0.01). Responders had a significantly higher level of VWF at T0. Finally, in a multivariate model analysis, VWF and ADAMTS-13 in resulted significant predictors of CEPI-CT response (P = 0.02). HRP detected by PFA-100 in acute myocardial infarction is reversible by DD of aspirin and clopidogrel; the response is predicted by basal levels of VWF and ADAMTS-13. PFA-100 may be a useful tool to risk stratification in acute coronary syndromes given its sensitivity to VWF.

  5. A reflective learning report about the implementation and impacts of Psychological First Aid (PFA) in Gaza.

    PubMed

    Schafer, Alison; Snider, Leslie; Sammour, Rania

    2016-01-01

    Psychological First Aid (PFA) is the recommended immediate psychosocial response during crises. As PFA is now widely implemented in crises worldwide, there are increasing calls to evaluate its effectiveness. World Vision used PFA as a fundamental component of their emergency response following the 2014 conflict in Gaza. Anecdotal reports from Gaza suggest a range of benefits for those who received PFA. Though not intending to undertake rigorous research, World Vision explored learnings about PFA in Gaza through Focus Group Discussions with PFA providers, Gazan women, men and children and a Key Informant Interview with a PFA trainer. The qualitative analyses aimed to determine if PFA helped individuals to feel safe, calm, connected to social supports, hopeful and efficacious - factors suggested by the disaster literature to promote coping and recovery (Hobfoll et al., 2007). Results show positive psychosocial benefits for children, women and men receiving PFA, confirming that PFA contributed to: safety, reduced distress, ability to engage in calming practices and to support each other, and a greater sense of control and hopefulness irrespective of their adverse circumstances. The data shows that PFA formed an important part of a continuum of care to meet psychosocial needs in Gaza and served as a gateway for addressing additional psychosocial support needs. A "whole-of-family" approach to PFA showed particularly strong impacts and strengthened relationships. Of note, the findings from World Vision's implementation of PFA in Gaza suggests that future PFA research go beyond a narrow focus on clinical outcomes, to a wider examination of psychosocial, familial and community-based outcomes.

  6. A reflective learning report about the implementation and impacts of Psychological First Aid (PFA) in Gaza

    PubMed Central

    Schafer, Alison; Snider, Leslie; Sammour, Rania

    2016-01-01

    Abstract Psychological First Aid (PFA) is the recommended immediate psychosocial response during crises. As PFA is now widely implemented in crises worldwide, there are increasing calls to evaluate its effectiveness. World Vision used PFA as a fundamental component of their emergency response following the 2014 conflict in Gaza. Anecdotal reports from Gaza suggest a range of benefits for those who received PFA. Though not intending to undertake rigorous research, World Vision explored learnings about PFA in Gaza through Focus Group Discussions with PFA providers, Gazan women, men and children and a Key Informant Interview with a PFA trainer. The qualitative analyses aimed to determine if PFA helped individuals to feel safe, calm, connected to social supports, hopeful and efficacious – factors suggested by the disaster literature to promote coping and recovery (Hobfoll et al., 2007). Results show positive psychosocial benefits for children, women and men receiving PFA, confirming that PFA contributed to: safety, reduced distress, ability to engage in calming practices and to support each other, and a greater sense of control and hopefulness irrespective of their adverse circumstances. The data shows that PFA formed an important part of a continuum of care to meet psychosocial needs in Gaza and served as a gateway for addressing additional psychosocial support needs. A “whole-of-family” approach to PFA showed particularly strong impacts and strengthened relationships. Of note, the findings from World Vision's implementation of PFA in Gaza suggests that future PFA research go beyond a narrow focus on clinical outcomes, to a wider examination of psychosocial, familial and community-based outcomes. PMID:28229012

  7. Assessment of clopidogrel non-response by the PFA-100 system using the new test cartridge INNOVANCE PFA P2Y.

    PubMed

    Linnemann, Birgit; Schwonberg, Jan; Rechner, Andreas R; Mani, Helen; Lindhoff-Last, Edelgard

    2010-06-01

    Until now, the PFA-100 system has been considered unsuitable for monitoring clopidogrel efficacy. The authors evaluated platelet function in peripheral arterial occlusive disease (PAOD) patients using a new PFA-100(R) test cartridge (product name: INNOVANCE PFA P2Y*) specifically designed for this purpose. Twenty-two stable PAOD patients on antithrombotic therapy with clopidogrel alone (n = 22) and 18 patients undergoing a peripheral catheter intervention, preliminarily treated with 100 mg/day of aspirin followed by co-administration of clopidogrel (loading dose 300 mg, maintenance dose 75 mg/day), were enrolled in this study. Defining non-responsiveness to clopidogrel as an aggregation response within the reference range (90% central interval), four (18.2%) non-responders using light transmittance aggregometry (LTA) induced by 5 microM adenosine diphosphate (ADP) and six (27.3%) non-responders using LTA induced by 2 microM ADP (LateAggr >72.1% and >42.9%, respectively) were identified. INNOVANCE PFA P2Y* determined six (27.3%) non-responders (CT < 87 s). Agreement between the two aggregometry assays and INNOVANCE PFA P2Y* on the definition of clopidogrel response and non-response exceeded 70%. Only three patients were uniformly identified as clopidogrel non-responders by all three assays. When clopidogrel was co-administered with aspirin, two (11.1%) non-responders to clopidogrel were detected with INNOVANCE PFA P2Y*, whereas ADP-induced LTA found all patients to be responsive. INNOVANCE PFA P2Y* appears to be suitable for monitoring the effect of clopidogrel on platelet function. Its sensitivity in detecting responsiveness or non-responsiveness to clopidogrel is comparable to ADP-induced LTA. Additional prospective studies are needed to clarify the clinical relevance of the test results and classification obtained with INNOVANCE PFA P2Y*.

  8. Excitation condition analysis of guided wave on PFA tubes for ultrasonic flow meter.

    PubMed

    Li, Xuan; Xiao, Xufeng; Cao, Li

    2016-12-01

    Impurity accumulation, which decreases the accuracy of flow measurement, is a critical problem when applying Z-shaped or U-shaped ultrasonic flow meters on straight PFA tubes. It can be expected that the guided wave can be used to implement flow measurement on straight PFA tubes. In this paper, the propagation of guided wave is explained by finite element simulations for the flow meter design. Conditions of guided wave generation, including the excitation frequency and the wedge structure, are studied in the simulations. The wedge is designed as a cone which is friendly to be manufactured and installed. The cone angle, the piezoelectric wafer's resonant frequency and the vibration directions are studied in the simulations. The simulations shows that the propagation of guided wave in thin PFA tubes is influenced by the piezoelectric wafers' resonant frequency and the vibration direction when the mode is on the 'water line'. Based on the results of the simulations, an experiment is conducted to verify the principles of excitation conditions, which performs flow measurement on a straight PFA tube well. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. The Johns Hopkins model of psychological first aid (RAPID-PFA): curriculum development and content validation.

    PubMed

    Everly, George S; Barnett, Daniel J; Links, Jonathan M

    2012-01-01

    There appears to be virtual universal endorsement of the need for and value of acute "psychological first aid" (PFA) in the wake of trauma and disasters. In this paper, we describe the development of the curriculum for The Johns Hopkins RAPID-PFA model of psychological first aid. We employed an adaptation of the basic framework for the development of a clinical science as recommended by Millon which entailed: historical review, theoretical development, and content validation. The process of content validation of the RAPID-PFA curriculum entailed the assessment of attitudes (confidence in the application of PFA interventions, preparedness in the application of PFA); knowledge related to the application of immediate mental health interventions; and behavior (the ability to recognize clinical markers in the field as assessed via a videotape recognition exercise). Results of the content validation phase suggest the six-hour RAPID-PFA curriculum, initially based upon structural modeling analysis, can improve confidence in the application of PFA interventions, preparedness in the application of PFA, knowledge related to the application of immediate mental health interventions, and the ability to recognize clinical markers in the field as assessed via a videotape recognition exercise.

  10. GENOA-PFA: Progressive Fracture in Composites Simulated Computationally

    NASA Technical Reports Server (NTRS)

    Murthy, Pappu L. N.

    2000-01-01

    GENOA-PFA is a commercial version of the Composite Durability Structural Analysis (CODSTRAN) computer program that simulates the progression of damage ultimately leading to fracture in polymer-matrix-composite (PMC) material structures under various loading and environmental conditions. GENOA-PFA offers several capabilities not available in other programs developed for this purpose, making it preferable for use in analyzing the durability and damage tolerance of complex PMC structures in which the fiber reinforcements occur in two- and three-dimensional weaves and braids. GENOA-PFA implements a progressive-fracture methodology based on the idea that a structure fails when flaws that may initially be small (even microscopic) grow and/or coalesce to a critical dimension where the structure no longer has an adequate safety margin to avoid catastrophic global fracture. Damage is considered to progress through five stages: (1) initiation, (2) growth, (3) accumulation (coalescence of propagating flaws), (4) stable propagation (up to the critical dimension), and (5) unstable or very rapid propagation (beyond the critical dimension) to catastrophic failure. The computational simulation of progressive failure involves formal procedures for identifying the five different stages of damage and for relating the amount of damage at each stage to the overall behavior of the deteriorating structure. In GENOA-PFA, mathematical modeling of the composite physical behavior involves an integration of simulations at multiple, hierarchical scales ranging from the macroscopic (lamina, laminate, and structure) to the microscopic (fiber, matrix, and fiber/matrix interface), as shown in the figure. The code includes algorithms to simulate the progression of damage from various source defects, including (1) through-the-thickness cracks and (2) voids with edge, pocket, internal, or mixed-mode delaminations.

  11. Molecular heterogeneity and CXorf67 alterations in posterior fossa group A (PFA) ependymomas.

    PubMed

    Pajtler, Kristian W; Wen, Ji; Sill, Martin; Lin, Tong; Orisme, Wilda; Tang, Bo; Hübner, Jens-Martin; Ramaswamy, Vijay; Jia, Sujuan; Dalton, James D; Haupfear, Kelly; Rogers, Hazel A; Punchihewa, Chandanamali; Lee, Ryan; Easton, John; Wu, Gang; Ritzmann, Timothy A; Chapman, Rebecca; Chavez, Lukas; Boop, Fredrick A; Klimo, Paul; Sabin, Noah D; Ogg, Robert; Mack, Stephen C; Freibaum, Brian D; Kim, Hong Joo; Witt, Hendrik; Jones, David T W; Vo, Baohan; Gajjar, Amar; Pounds, Stan; Onar-Thomas, Arzu; Roussel, Martine F; Zhang, Jinghui; Taylor, J Paul; Merchant, Thomas E; Grundy, Richard; Tatevossian, Ruth G; Taylor, Michael D; Pfister, Stefan M; Korshunov, Andrey; Kool, Marcel; Ellison, David W

    2018-06-16

    Of nine ependymoma molecular groups detected by DNA methylation profiling, the posterior fossa type A (PFA) is most prevalent. We used DNA methylation profiling to look for further molecular heterogeneity among 675 PFA ependymomas. Two major subgroups, PFA-1 and PFA-2, and nine minor subtypes were discovered. Transcriptome profiling suggested a distinct histogenesis for PFA-1 and PFA-2, but their clinical parameters were similar. In contrast, PFA subtypes differed with respect to age at diagnosis, gender ratio, outcome, and frequencies of genetic alterations. One subtype, PFA-1c, was enriched for 1q gain and had a relatively poor outcome, while patients with PFA-2c ependymomas showed an overall survival at 5 years of > 90%. Unlike other ependymomas, PFA-2c tumors express high levels of OTX2, a potential biomarker for this ependymoma subtype with a good prognosis. We also discovered recurrent mutations among PFA ependymomas. H3 K27M mutations were present in 4.2%, occurring only in PFA-1 tumors, and missense mutations in an uncharacterized gene, CXorf67, were found in 9.4% of PFA ependymomas, but not in other groups. We detected high levels of wildtype or mutant CXorf67 expression in all PFA subtypes except PFA-1f, which is enriched for H3 K27M mutations. PFA ependymomas are characterized by lack of H3 K27 trimethylation (H3 K27-me3), and we tested the hypothesis that CXorf67 binds to PRC2 and can modulate levels of H3 K27-me3. Immunoprecipitation/mass spectrometry detected EZH2, SUZ12, and EED, core components of the PRC2 complex, bound to CXorf67 in the Daoy cell line, which shows high levels of CXorf67 and no expression of H3 K27-me3. Enforced reduction of CXorf67 in Daoy cells restored H3 K27-me3 levels, while enforced expression of CXorf67 in HEK293T and neural stem cells reduced H3 K27-me3 levels. Our data suggest that heterogeneity among PFA ependymomas could have clinicopathologic utility and that CXorf67 may have a functional role in these tumors.

  12. PFA-100-measured aspirin resistance is the predominant risk factor for hospitalized cardiovascular events in aspirin-treated patients: A 5-year cohort study.

    PubMed

    Chen, H Y; Chou, P

    2018-04-01

    Aspirin therapy is the clinical gold standard for the prevention of cardiovascular events. However, cardiovascular events still develop in some patients undergoing aspirin therapy. Many laboratory methods exist for measuring aspirin resistance. Using the platelet Function Analyzer (PFA)-100 system, we aimed to determine the effect of aspirin resistance on hospitalized cardiovascular events (hCVE) in a 5-year follow-up cohort. We also sought to determine the impact of aspirin resistance on the relationship between common cardiovascular risk factors and cardiovascular hospitalization. Aspirin resistance was evaluated in aspirin-treated patients from the outpatient department. A total of 465 patients during a 5-year follow-up period were included in this study. The primary endpoint of the study was hospitalization for any acute cardiovascular event. The prevalence and associated risk factors of acute cardiovascular events were evaluated. Aspirin resistance was prevalent in 91 (20.0%) of 465 patients. Prior hospitalization history of cardiovascular events was highly associated with aspirin resistance (P = .001). At the 5-year follow-up, cardiovascular events were found to have developed in 11 patients (8 stroke and 3 myocardial infarction) who exhibited aspirin resistance (12.1%) and in 9 (4 stroke and 5 myocardial infarction) patients who did not exhibit aspirin resistance (2.4%) (P < .001). At the 5-year follow-up, multivariate logistic regression analysis results showed a strong association between aspirin resistance and cardiovascular events (adjusted odds ratio 4.28; 95% CI: 1.64-11.20; P = .03). PFA-100 measurements of aspirin resistance correlate with hCVE, as evidenced by both the past medical history and the 5-year follow-up. The logistic regression analysis results showed that aspirin resistance plays a larger role in hospitalized cardiovascular disease than do other cardiovascular risk factors. © 2017 John Wiley & Sons Ltd.

  13. Radiolytic preparation of ETFE and PFA based anion exchange membranes for alkaline fuel cell

    NASA Astrophysics Data System (ADS)

    Ko, Beom-Seok; Sohn, Joon-Yong; Nho, Young-Chang; Shin, Junhwa

    2011-11-01

    In this study, a versatile monomer, vinylbenzyl chloride (VBC) was radiolytically grafted onto a partially fluorinated ETFE and perfluorinated polymer PFA films. The VBC grafted films were treated with trimethylamine to prepare the alkaline anion exchange membranes (AAEMs). No significant differences in the ion exchange capacities and water uptakes were observed between the ETFE and PFA based AAEMs with similar degree of grafting (DOG). However, the distribution patterns of the graft chains over the cross-section of the ETFE and PFA based AAEMs were found to be quite different; the even distribution was observed from the ETFE based AAEMs while the uneven distribution was observed from the PFA based AAEMs. It was also found that the PFA based AAEMs have the higher ionic conductivity and chemical stability, compared to the ETFE based AAEMs.

  14. Can the Platelet Function Analyzer (PFA)-100 test substitute for the template bleeding time in routine clinical practice?

    PubMed

    Francis, J; Francis, D; Larson, L; Helms, E; Garcia, M

    1999-01-01

    The bleeding time (BT) is widely used in clinical medicine as a screening test of platelet function, although its deficiencies in such a role are well recognized. The Platelet Function Analyzer (PFA)-100 measures the ability of platelets activated in a high-shear environment to occlude an aperture in a membrane treated with collagen and epinephrine (CEPI) or collagen and ADP (CADP). The time taken for flow across the membrane to stop (closure time) is recorded. This study compared the PFA-100 with the BT as a screening test of platelet dysfunction in 113 hospital inpatients. The PFA-100 test was performed initially using the CEPI cartridge; CADP tests were performed on those with abnormal (> 163 s) CEPI closure times. Whole blood platelet aggregation studies and chart review were performed on patients in whom the BT and PFA-100 results did not agree.Abnormal bleeding times and PFA-100 results were obtained in 20.4% and 35.4% of patients, respectively. The results of BT and PFA-100 agreed in 74.3% of patients. Of the 29 patients in whom the BT and PFA-100 results were discordant, whole blood platelet aggregation studies supported the PFA-100 result in 25 (86.2%). The PFA-100 was more sensitive to aspirin-induced platelet dysfunction and was more rapidly and cheaply performed than the BT. Since the PFA-100 test reflects platelet function better than the BT, we conclude that this test could replace the BT as a first-line screening test for platelet dysfunction in clinical practice.

  15. The development of a model of psychological first aid for non-mental health trained public health personnel: the Johns Hopkins RAPID-PFA.

    PubMed

    Everly, George S; Lee McCabe, O; Semon, Natalie L; Thompson, Carol B; Links, Jonathan M

    2014-01-01

    The Johns Hopkins Center for Public Health Preparedness, which houses the Centers for Disease Control and Prevention-funded Preparedness and Emergency Response Learning Center, has been addressing the challenge of disaster-caused behavioral health surge by conducting training programs in psychological first aid (PFA) for public health professionals. This report describes our approach, named RAPID-PFA, and summarizes training evaluation data to determine if relevant knowledge, skills, and attitudes are imparted to trainees to support effective PFA delivery. In the wake of disasters, there is an increase in psychological distress and dysfunction among survivors and first responders. To meet the challenges posed by this surge, a professional workforce trained in PFA is imperative. More than 1500 participants received a 1-day RAPID-PFA training. Pre-/postassessments were conducted to measure (a) required knowledge to apply PFA; (b) perceived self-efficacy, that is, belief in one's own ability, to apply PFA techniques; and (c) confidence in one's own resilience in a crisis context. Statistical techniques were used to validate the extent to which the survey successfully measured individual PFA constructs, that is, unidimensionality, and to quantify the reliability of the assessment tool. Statistically significant pre-/postimprovements were observed in (a) knowledge items supportive of PFA delivery, (b) perceived self-efficacy to apply PFA interventions, and (c) confidence about being a resilient PFA provider. Cronbach alpha coefficients ranging from 0.87 to 0.90 suggested that the self-reported measures possessed sufficient internal consistency. Findings were consistent with our pilot work, and with our complementary research initiatives validating a variant of RAPID-PFA with faith communities. The RAPID-PFA model promises to be a broadly applicable approach to extending community behavioral health surge capacity. Relevant next steps include evaluating the effectiveness

  16. Exploratory factor analysis of the 12-item Functional Assessment of Chronic Illness Therapy-Spiritual Well-Being Scale in people newly diagnosed with advanced cancer.

    PubMed

    Bai, Mei; Dixon, Jane K

    2014-01-01

    The purpose of this study was to reexamine the factor pattern of the 12-item Functional Assessment of Chronic Illness Therapy-Spiritual Well-Being Scale (FACIT-Sp-12) using exploratory factor analysis in people newly diagnosed with advanced cancer. Principal components analysis (PCA) and 3 common factor analysis methods were used to explore the factor pattern of the FACIT-Sp-12. Factorial validity was assessed in association with quality of life (QOL). Principal factor analysis (PFA), iterative PFA, and maximum likelihood suggested retrieving 3 factors: Peace, Meaning, and Faith. Both Peace and Meaning positively related to QOL, whereas only Peace uniquely contributed to QOL. This study supported the 3-factor model of the FACIT-Sp-12. Suggestions for revision of items and further validation of the identified factor pattern were provided.

  17. Electronic health record analysis via deep poisson factor models

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

    Henao, Ricardo; Lu, James T.; Lucas, Joseph E.

    Electronic Health Record (EHR) phenotyping utilizes patient data captured through normal medical practice, to identify features that may represent computational medical phenotypes. These features may be used to identify at-risk patients and improve prediction of patient morbidity and mortality. We present a novel deep multi-modality architecture for EHR analysis (applicable to joint analysis of multiple forms of EHR data), based on Poisson Factor Analysis (PFA) modules. Each modality, composed of observed counts, is represented as a Poisson distribution, parameterized in terms of hidden binary units. In-formation from different modalities is shared via a deep hierarchy of common hidden units. Activationmore » of these binary units occurs with probability characterized as Bernoulli-Poisson link functions, instead of more traditional logistic link functions. In addition, we demon-strate that PFA modules can be adapted to discriminative modalities. To compute model parameters, we derive efficient Markov Chain Monte Carlo (MCMC) inference that scales efficiently, with significant computational gains when compared to related models based on logistic link functions. To explore the utility of these models, we apply them to a subset of patients from the Duke-Durham patient cohort. We identified a cohort of over 12,000 patients with Type 2 Diabetes Mellitus (T2DM) based on diagnosis codes and laboratory tests out of our patient population of over 240,000. Examining the common hidden units uniting the PFA modules, we identify patient features that represent medical concepts. Experiments indicate that our learned features are better able to predict mortality and morbidity than clinical features identified previously in a large-scale clinical trial.« less

  18. Electronic health record analysis via deep poisson factor models

    DOE PAGES

    Henao, Ricardo; Lu, James T.; Lucas, Joseph E.; ...

    2016-01-01

    Electronic Health Record (EHR) phenotyping utilizes patient data captured through normal medical practice, to identify features that may represent computational medical phenotypes. These features may be used to identify at-risk patients and improve prediction of patient morbidity and mortality. We present a novel deep multi-modality architecture for EHR analysis (applicable to joint analysis of multiple forms of EHR data), based on Poisson Factor Analysis (PFA) modules. Each modality, composed of observed counts, is represented as a Poisson distribution, parameterized in terms of hidden binary units. In-formation from different modalities is shared via a deep hierarchy of common hidden units. Activationmore » of these binary units occurs with probability characterized as Bernoulli-Poisson link functions, instead of more traditional logistic link functions. In addition, we demon-strate that PFA modules can be adapted to discriminative modalities. To compute model parameters, we derive efficient Markov Chain Monte Carlo (MCMC) inference that scales efficiently, with significant computational gains when compared to related models based on logistic link functions. To explore the utility of these models, we apply them to a subset of patients from the Duke-Durham patient cohort. We identified a cohort of over 12,000 patients with Type 2 Diabetes Mellitus (T2DM) based on diagnosis codes and laboratory tests out of our patient population of over 240,000. Examining the common hidden units uniting the PFA modules, we identify patient features that represent medical concepts. Experiments indicate that our learned features are better able to predict mortality and morbidity than clinical features identified previously in a large-scale clinical trial.« less

  19. Evaluation of platelet function in dogs with cardiac disease using the PFA-100 platelet function analyzer.

    PubMed

    Clancey, Noel; Burton, Shelley; Horney, Barbara; Mackenzie, Allan; Nicastro, Andrea; Côté, Etienne

    2009-09-01

    Cardiac disease has the potential to alter platelet function in dogs. Evaluation of platelet function using the PFA-100 analyzer in dogs of multiple breeds and with a broad range of cardiac conditions would help clarify the effect of cardiac disease on platelets. The objective of this study was to assess differences in closure time (CT) in dogs with cardiac disease associated with murmurs, when compared with that of healthy dogs. Thirty-nine dogs with cardiac murmurs and turbulent blood flow as determined echocardiographically were included in the study. The dogs represented 23 different breeds. Dogs with murmurs were further divided into those with atrioventricular valvular insufficiency (n=23) and subaortic stenosis (n=9). Fifty-eight clinically healthy dogs were used as controls. CTs were determined in duplicate on a PFA-100 analyzer using collagen/ADP cartridges. Compared with CTs in the control group (mean+/-SD, 57.6+/-5.9 seconds; median, 56.5 seconds; reference interval, 48.0-77.0 seconds), dogs with valvular insufficiency (mean+/-SD, 81.9+/-26.3 seconds; median, 78.0 seconds; range, 52.5-187 seconds), subaortic stenosis (71.4+/-16.5 seconds; median, 66.0 seconds; range, 51.5-95.0 seconds), and all dogs with murmurs combined (79.6+/-24.1 seconds; median, 74.0 seconds; range, 48.0-187 seconds) had significantly prolonged CTs (P<.01). The PFA-100 analyzer is useful in detecting platelet function defects in dogs with cardiac murmurs, most notably those caused by mitral and/or tricuspid valvular insufficiency or subaortic stenosis. The form of turbulent blood flow does not appear to be an important factor in platelet hypofunction in these forms of cardiac disease.

  20. How to Construct More Accurate Student Models: Comparing and Optimizing Knowledge Tracing and Performance Factor Analysis

    ERIC Educational Resources Information Center

    Gong, Yue; Beck, Joseph E.; Heffernan, Neil T.

    2011-01-01

    Student modeling is a fundamental concept applicable to a variety of intelligent tutoring systems (ITS). However, there is not a lot of practical guidance on how to construct and train such models. This paper compares two approaches for student modeling, Knowledge Tracing (KT) and Performance Factors Analysis (PFA), by evaluating their predictive…

  1. Epidémiologie des PFA et les performances du système de surveillance en Mauritanie de 2008 à 2012

    PubMed Central

    Doumtsop, Jean Gérard Tatou; Khalef, Ishagh; Diakite, Med Lemine Brahim; Boubker, Naouri

    2014-01-01

    Introduction La Commission Régionale de Certification de l'Eradication de la poliomyélite pour l'Afrique(CRCA) en session à Brazzaville du 8 au 10 octobre 2007 avait déclaré la Mauritanie « libérée de la poliomyélite ». Objectif Décrire l’épidémiologie des PFA (Paralysies flasques aigues) et évaluer les indicateurs de performance du système de surveillance pour la période de 2008 à 2012 ayant suivi cette déclaration. Méthodes Les données du service de surveillance épidémiologique ont été nettoyées et analysées à l'aide du logiciel Epi-infoversion 3.4.3 (CDC Atlanta). Résultats 319 cas de PFA ont été notifié soit une incidence moyenne de 4.61/100000 enfants de moins de 15 ans par an. La distribution des cas cumulés par mois montre une importante notification des cas PFA pendant la période de Février à Juillet et à la suite de l’épidémie de 2009 alors que l'incidence des cas confirmés a été plus importante entre Novembre et Février. L’âge moyen était de 4ans (E.T. ±4ans) et 77.4% avaient un âge = 5ans. 18 cas de PFA ont été confirmés poliovirus sauvage(PVS) dont 6 en 2009 et 12 en 2010 et tous d'importation. L’âge moyen était de 3.4 ans (E.T ±2.6 ans). 44,4% étaient des filles et 55.5% garçons. Cette proportion était proche de celle des PFA non polio (45.1% versus 54.9%). 61% avaient reçu au plus une dose de vaccin polio orale (VPO) pour les cas de PFA polio contre 7.4% pour les PFA non polio. Aucune discrimination de genre n'a été observé sur la population des PFA ayant reçu une dose au plus (ratio-sexe= 16/17=0.94). La fièvre était présente pour 90%des cas de PFA non polio contre 85% pour les cas PVS. Cette fièvre à progresser en 3 jours pour tous les cas de PVS et pour 82,7% des cas de PFA non polio. Le taux d'hospitalisation était de 13.6% pour les cas de PFA non polio contre 89% pour les PFA polio. Dans tous les deux groupes, les membres de prédilection étaient d'abord l'un des 2 membres

  2. The use of psychological first aid (PFA) training among nurses to enhance population resiliency.

    PubMed

    Everly, George S; Barnett, Daniel J; Sperry, Nancy L; Links, Jonathan M

    2010-01-01

    Disaster mental health research has found that psychological casualties from a given disaster can be expected to far outnumber physical casualties. Amidst a shortage of mental health professionals and against the backdrop of natural disasters, continued terrorism, and pandemic influenza, there is a striking need to expand and operationalize available human resources to enhance the psychological resiliency of those affected. Through the utilization of psychological first aid (PFA) as an early crisis intervention tool, and by virtue of their occupation and experience, nurses are particularly well-suited to assume a leadership role in expanding the disaster mental health presence beyond the existing cadre of mental health clinicians. Here, we characterize the importance of integrating PFA in the context of other nursing functions, to augment mental health surge capacity in disaster settings.

  3. Evaluation of the effect of ketoprofen and carprofen on platelet function in dogs studied by PFA-100 point-of-care analyser.

    PubMed

    Gaál, T; Halmay, Dóra; Kocsis, R; Abonyi-Tóth, Z

    2007-09-01

    The effect of two nonsteroidal anti-inflammatory drugs (carprofen and ketoprofen) on platelet adhesion and aggregation functions was evaluated by the PFA-100 analyser (Dade-Behring, CA, U.S.A.) using its collagen-adenosine diphosphate (ADP) and collagen-epinephrine (EPI) cartridges. The function of platelets was evaluated in 55 healthy dogs, in 7 dogs treated with ketoprofen and in 31 dogs treated with carprofen in a therapeutic dose for minimum 5 days. The therapeutic doses of carprofen had no effect on the closure time of PFA-100 (which is the marker of platelet function) but ketoprofen caused a significant increase when using collagen-EPI stimulation The closure times for both the healthy (control) and the treated dogs using EPI cartridges were often longer than the upper default cut-off point (300 sec) of the device. The PFA-100 analyser with collagen-ADP cartridges could be a useful tool for veterinary applications including the evaluation of platelet aggregation in dogs treated with NSAIDs. The upper cut-off point of PFA-100 might be extended.

  4. Development of a penetration friction apparatus (PFA) to measure the frictional performance of surgical suture.

    PubMed

    Zhang, Gangqiang; Ren, Tianhui; Lette, Walter; Zeng, Xiangqiong; van der Heide, Emile

    2017-10-01

    Nowadays there is a wide variety of surgical sutures available in the market. Surgical sutures have different sizes, structures, materials and coatings, whereas they are being used for various surgeries. The frictional performances of surgical sutures have been found to play a vital role in their functionality. The high friction force of surgical sutures in the suturing process may cause inflammation and pain to the person, leading to a longer recovery time, and the second trauma of soft or fragile tissue. Thus, the investigation into the frictional performance of surgical suture is essential. Despite the unquestionable fact, little is actually known on the friction performances of surgical suture-tissue due to the lack of appropriate test equipment. This study presents a new penetration friction apparatus (PFA) that allowed for the evaluation of the friction performances of various surgical needles and sutures during the suturing process, under different contact conditions. It considered the deformation of tissue and can realize the puncture force measurements of surgical needles as well as the friction force of surgical sutures. The developed PFA could accurately evaluate and understand the frictional behaviour of surgical suture-tissue in the simulating clinical conditions. The forces measured by the PFA showed the same trend as that reported in literatures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Effect of Response Reduction Factor on Peak Floor Acceleration Demand in Mid-Rise RC Buildings

    NASA Astrophysics Data System (ADS)

    Surana, Mitesh; Singh, Yogendra; Lang, Dominik H.

    2017-06-01

    Estimation of Peak Floor Acceleration (PFA) demand along the height of a building is crucial for the seismic safety of nonstructural components. The effect of the level of inelasticity, controlled by the response reduction factor (strength ratio), is studied using incremental dynamic analysis. A total of 1120 nonlinear dynamic analyses, using a suite of 30 recorded ground motion time histories, are performed on mid-rise reinforced-concrete (RC) moment-resisting frame buildings covering a wide range in terms of their periods of vibration. The obtained PFA demands are compared with some of the major national seismic design and retrofit codes (IS 1893 draft version, ASCE 41, EN 1998, and NZS 1170.4). It is observed that the PFA demand at the building's roof level decreases with increasing period of vibration as well as with strength ratio. However, current seismic building codes do not account for these effects thereby producing very conservative estimates of PFA demands. Based on the identified parameters affecting the PFA demand, a model to obtain the PFA distribution along the height of a building is proposed. The proposed model is validated with spectrum-compatible time history analyses of the considered buildings with different strength ratios.

  6. Maps, Models and Data from Southeastern Great Basin PFA, Phase II Project

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

    Nash, Greg

    This submission includes composite risk segment models in raster format for permeability, heat of the earth, and MT, as well as the final PFA model of geothermal exploration risk in Southwestern Utah, USA. Additionally, this submission has data regarding hydrothermally altered areas, and opal sinter deposits in the study area. All of this information lends to the understanding and exploration for hidden geothermal systems in the area.

  7. fabH deletion increases DHA production in Escherichia coli expressing Pfa genes.

    PubMed

    Giner-Robles, Laura; Lázaro, Beatriz; de la Cruz, Fernando; Moncalián, Gabriel

    2018-06-08

    Some marine bacteria, such as Moritella marina, produce the nutraceutical docosahexaenoic acid (DHA) thanks to a specific enzymatic complex called Pfa synthase. Escherichia coli heterologously expressing the pfa gene cluster from M. marina also produces DHA. The aim of this study was to find genetic or metabolic conditions to increase DHA production in E. coli. First, we analysed the effect of the antibiotic cerulenin, showing that DHA production increased twofold. Then, we tested a series of single gene knockout mutations affecting fatty acid biosynthesis, in order to optimize the synthesis of DHA. The most effective mutant, fabH, showed a threefold increase compared to wild type strain. The combination of cerulenin inhibition and fabH deletion rendered a 6.5-fold improvement compared to control strain. Both strategies seem to have the same mechanism of action, in which fatty acid synthesis via the canonical pathway (fab pathway) is affected in its first catalytic step, which allows the substrates to be used by the heterologous pathway to synthesize DHA. DHA-producing E. coli strain that carries a fabH gene deletion boosts DHA production by tuning down the competing canonical biosynthesis pathway. Our approach can be used for optimization of DHA production in different organisms.

  8. AmeriFlux US-PFa Park Falls/WLEF

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

    Desai, Ankur

    This is the AmeriFlux version of the carbon flux data for the site US-PFa Park Falls/WLEF. Site Description - The flux footprint encompasses a highly heterogeneous landscape of upland forests and wetlands (forested and nonforested). The forests are mainly deciduous but also include substantial coniferous coverage. The upland/lowland variability occurs on spatial scales of a few hundred meters. This heterogeneous landscape is further complicated by a nonuniform, small scale mosaic of thinning and clearcutting of the forest. At larger scales (1 km or greater) the forest cover mosaic is quite homogeneous for many kilometers. The site was chosen not formore » study of a simple stand, but for upscaling experiments. The daytime fetch of flux measurements from the 396m level is on the order of 5-10 km, yielding a flux footprint roughly 100x the area of a typical stand-level flux tower. AC power (tower is a TV transmitter).« less

  9. SE Great Basin Play Fairway Analysis

    DOE Data Explorer

    Adam Brandt

    2015-11-15

    This submission includes a Na/K geothermometer probability greater than 200 deg C map, as well as two play fairway analysis (PFA) models. The probability map acts as a composite risk segment for the PFA models. The PFA models differ in their application of magnetotelluric conductors as composite risk segments. These PFA models map out the geothermal potential in the region of SE Great Basin, Utah.

  10. Resilient landscapes in Mediterranean urban areas: Understanding factors influencing forest trends.

    PubMed

    Tomao, Antonio; Quatrini, Valerio; Corona, Piermaria; Ferrara, Agostino; Lafortezza, Raffaele; Salvati, Luca

    2017-07-01

    Urban and peri-urban forests are recognized as basic elements for Nature-Based Solutions (NBS), as they preserve and may increase environmental quality in urbanized contexts. For this reason, the amount of forest land per inhabitant is a pivotal efficiency indicator to be considered in the sustainable governance, land management, planning and design of metropolitan areas. The present study illustrates a multivariate analysis of per-capita forest area (PFA) in mainland Attica, the urban region surrounding Athens, Greece. Attica is considered a typical case of Mediterranean urbanization where planning has not regulated urban expansion and successive waves of spontaneous growth have occurred over time. In such a context, an analysis of factors that can affect landscape changes in terms of PFA may inform effective strategies for the sustainable management of socio-ecological local systems in light of the NBS perspective. A total of 26 indicators were collected per decade at the municipal scale in the study area with the aim to identify the factors most closely associated to the amount of PFA. Indicators of urban morphology and functions have been considered together with environmental and topographical variables. In Attica, PFA showed a progressive decrease between 1960 and 2010. In particular, PFA progressively declined (1980, 1990) along fringe areas surrounding Athens and in peri-urban districts experiencing dispersed expansion of residential settlements. Distance from core cities and from the seacoast, typical urban functions (e.g., multiple use of buildings and per capita built-up area) and percentage of agricultural land-use in each municipality are the variables most associated with high PFA. In recent years, some municipalities have shown an expansion of forest cover, mainly due to land abandonment and forest recolonization. Findings from this case study have allowed us to identify priorities for NBS at metropolitan level aimed at promoting more sustainable

  11. Interfacial chemical oxidative synthesis of multifunctional polyfluoranthene† †Electronic supplementary information (ESI) available: The optimization of polymerization conditions, size distribution and morphology of the PFA particles, and solubility and DMSO solution in sunlight and in 365 nm UV of FA and PFA synthesized. See DOI: 10.1039/c4sc03890h Click here for additional data file.

    PubMed Central

    Liao, Yaozu

    2015-01-01

    A novel polyfluoranthene (PFA) exhibiting strong visual fluorescence emission, a highly amplified quenching effect, and widely controllable electrical conductivity is synthesized by the direct cationic oxidative polymerization of fluoranthene in a dynamic interface between n-hexane and nitromethane containing fluoranthene and FeCl3, respectively. A full characterization of the molecular structure signifies that the PFAs have a degree of polymerization from 22–50 depending on the polymerization conditions. A polymerization mechanism at the interface of the hexane/nitromethane biphasic system is proposed. The conductivity of the PFA is tunable from 6.4 × 10–6 to 0.074 S cm–1 by doping with HCl or iodine. The conductivity can be significantly enhanced to 150 S cm–1 by heat treatment at 1100 °C in argon. A PFA-based chemosensor shows a highly selective sensitivity for Fe3+ detection which is unaffected by other common metal ions. The detection of Fe3+ likely involves the synergistic effect of well-distributed π-conjugated electrons throughout the PFA helical chains that function as both the fluorophore and the receptor units. PMID:29142676

  12. Perforator flap based on the third perforator of the profunda femoris artery (PFA)-assisted closure of the free vertical posteromedial thigh (vPMT) flap donor site.

    PubMed

    Scaglioni, Mario F; Barth, Andrè A; Chen, Yen-Chou

    2018-06-19

    The primary closure of the vertical posteromedial thigh (vPMT) free flap donor site is very important to minimize donor site morbidity and maximize cosmetic appearance. However, sometimes due to the dimension of the defect, a vPMT flap is wider than the 8-10 cm requirement. The authors report their experience with the third perforator of the profunda femoris artery (PFA) during the vPMT free flap donor-site closure. Between January 2016 and December 2017, 5 patients underwent reconstruction of lower extremity (2 pts.) and head and neck (3 pts.) area with the free vPMT flaps. Attempts to close the vPMT free flap donor site directly failed due to the flaps' width (average: 11 cm) and pedicled perforator flaps based on the third perforator of the PFA at the distal thigh were harvested to close the defect primary without the use of a skin graft. The size of perforator flap based on 3rd perforator of PFA was on average 6 cm × 4 cm (ranged: 4-8 cm × 3-6 cm). In all patients, the third perforator of the PFA was identified and the perforator diameter was on average 2.0 mm (range, 1.8-2.2 mm). All perforators were musculocutaneous and single. The dimensions of the flaps were on average 6 cm × 4 cm (range: 4 to 8 cm × 3 to 6 cm). All flaps healed uneventfully without complications and the patients were satisfied with cosmetic and functional results at 6 months follow-up. The third perforator of the PFA may be an option to ensure primary closure of the PMT flap donor site, when a larger flap for reconstruction is needed with subsequent impossibility to achieve primary closure of the donor site. © 2018 Wiley Periodicals, Inc.

  13. Prevalence of ex vivo high on-treatment platelet reactivity on antiplatelet therapy after transient ischemic attack or ischemic stroke on the PFA-100(®) and VerifyNow(®).

    PubMed

    Kinsella, Justin A; Tobin, W Oliver; Cox, Dermot; Coughlan, Tara; Collins, Ronan; O'Neill, Desmond; Murphy, Raymond P; McCabe, Dominick J H

    2013-10-01

    The prevalence of ex vivo high on-treatment platelet reactivity (HTPR) to commonly prescribed antiplatelet regimens after transient ischemic attack (TIA) or ischemic stroke is uncertain. Platelet function inhibition was simultaneously assessed with modified light transmission aggregometry (VerifyNow; Accumetrics Inc, San Diego, CA) and with a moderately high shear stress platelet function analyzer (PFA-100; Siemens Medical Solutions USA, Inc, Malvern, PA) in a pilot, cross-sectional study of TIA or ischemic stroke patients. Patients were assessed on aspirin-dipyridamole combination therapy (n = 51) or clopidogrel monotherapy (n = 25). On the VerifyNow, HTPR on aspirin was identified in 4 of 51 patients (8%) on aspirin-dipyridamole combination therapy (≥ 550 aspirin reaction units on the aspirin cartridge). Eleven of 25 (44%) patients had HTPR on clopidogrel (≥ 194 P2Y12 reaction units on the P2Y12 cartridge). On the PFA-100, 21 of 51 patients (41%) on aspirin-dipyridamole combination therapy had HTPR on the collagen-epinephrine (C-EPI) cartridge. Twenty-three of 25 patients (92%) on clopidogrel had HTPR on the collagen-adenosine diphosphate (C-ADP) cartridge. The proportion of patients with antiplatelet HTPR was lower on the VerifyNow than PFA-100 in patients on both regimens (P < .001). The prevalence of ex vivo antiplatelet HTPR after TIA or ischemic stroke is markedly influenced by the method used to assess platelet reactivity. The PFA-100 C-ADP cartridge is not sensitive at detecting the antiplatelet effects of clopidogrel ex vivo. Larger prospective studies with the VerifyNow and with the PFA-100 C-EPI and recently released Innovance PFA P2Y cartridges (Siemens Medical Solutions USA, Inc) in addition to newer tests of platelet function are warranted to assess whether platelet function monitoring predicts clinical outcome in ischemic cerebrovascular disease. Copyright © 2013 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  14. Interoperability of 300 watt and 150 watt xenon arc solar simulators in sun protection factor and in UVA protection factor clinical testing.

    PubMed

    Martinez, Alexa; Roberts, Glenn; Garzarella, Katherine; Lutz, Michael; Caswell, Michael

    2013-04-01

    The purpose of these clinical trials was to determine if 300 W and 150 W xenon arc solar simulators (SSs) deliver the same sun protection factor (SPF) and UVA protection factor (PFA). First, the SPF of the P7 control standard and of the P2 control standard was determined, testing 20 subjects using the method described in the Food and Drug Administration (FDA) Final Monograph and using 150 W and 300 W SSs. In the second clinical trial, the PFA of the Japanese Cosmetic Industry Association (JCIA) control standard and of the P2 control standard was determined, testing 10 subjects using the method described in the JCIA Technical Bulletin and using 150 W and 300 W SSs. The SPF values for P7 control standard determined using the 150 W and 300 W SSs were 4.54 ± 0.35 and 4.61 ± 0.32, respectively. The SPF values for P2 control standard determined using the 150 W and 300 W SSs were 17.0 ± 0.9 and 16.7 ± 0.9, respectively. The resultant PFA values for JCIA control standard determined using the 150 W and 300 W SSs were 4.06 ± 0.70 and 4.06 ± 0.70, respectively. The resultant PFA values for P2 control standard determined using the 150 W and 300 W SSs were 3.28 ± 0.25 and 3.44 ± 0.39, respectively. As the values are essentially identical for SPF and for PFA, the 150 W and 300 W SSs can be used interchangeably for SPF and PFA determinations. © 2013 John Wiley & Sons A/S.

  15. Diffusion in cementitious materials. 2: Further investigations of chloride and oxygen diffusion in well-cured OPC and OPC/30%PFA pastes

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

    Ngala, V.T.; Page, C.L.; Parrott, L.J.

    1995-05-01

    Steady-state diffusion of dissolved oxygen and chloride ions in hydrated OPC and OPC/30%PFA pastes, hydrated for 2 weeks at 20 C and 10 weeks at 38 C, was studied at water/binder (w/s) ratios 0.4, 0.5, 0.6 and 0.7. Total porosity and a simple measure of capillary porosity, the volume fractions of the water lost in specimens from a saturated surface dry condition to a near-constant weight at 90.7% relative humidity, were also determined. The diffusion rate of chloride ions diminished markedly, to very low values, as the capillary porosity approached zero. For a given w/s ratio or capillary porosity themore » chloride ion diffusion coefficient for OPC/30%PFA pastes was about one order of magnitude smaller than that to OPC pastes. The rate of diffusion of dissolved oxygen also diminished as the capillary porosity reduced but it was still significant as the capillary porosity approached zero. For a given capillary porosity the oxygen diffusion coefficient for OPC/30%PFA pastes was about 30% smaller than that for OPC pastes. The results support the view that chloride ion diffusion in pastes of low capillary porosity is retarded by the surface charge of the hydrated cement gel. In contrast, the hydrated cement gel is much more permeable to the similarly-sized, neutral oxygen molecule.« less

  16. Utility of the PFA-100 instrument and the novel multiplate analyzer for the assessment of aspirin and clopidogrel effects on platelet function in patients with cardiovascular disease.

    PubMed

    Mueller, Thomas; Dieplinger, Benjamin; Poelz, Werner; Haltmayer, Meinhard

    2009-12-01

    This study evaluated the utility of the PFA-100 and the Multiplate analyzer for the assessment of aspirin and clopidogrel effects on platelet function in patients with cardiovascular disease. Platelet function was determined with the PFA-100 using collagen+epinephrine (CEPI) and collagen+adenosine-5'-diphosphate (CADP) cartridges, and with whole blood impedance aggregometry using the Multiplate ASPI and ADP+PG tests (aggregation triggered with arachidonic acid and ADP+ prostaglandin E1, respectively). Four study groups were identified from the 154 patients enrolled: patients without antiplatelet therapy, patients with 100 mg aspirin daily but without clopidogrel treatment, patients with 75 mg clopidogrel daily but without aspirin treatment, and patients with both 100 mg aspirin daily plus 75 mg clopidogrel daily. It was found that the PFA-100 instrument is useful for detection of aspirin but not for detection of a clopidogrel effect, while the Multiplate analyzer is useful for specific detection of both aspirin and clopidogrel effects on platelet function.

  17. The use of regression analysis in determining reference intervals for low hematocrit and thrombocyte count in multiple electrode aggregometry and platelet function analyzer 100 testing of platelet function.

    PubMed

    Kuiper, Gerhardus J A J M; Houben, Rik; Wetzels, Rick J H; Verhezen, Paul W M; Oerle, Rene van; Ten Cate, Hugo; Henskens, Yvonne M C; Lancé, Marcus D

    2017-11-01

    Low platelet counts and hematocrit levels hinder whole blood point-of-care testing of platelet function. Thus far, no reference ranges for MEA (multiple electrode aggregometry) and PFA-100 (platelet function analyzer 100) devices exist for low ranges. Through dilution methods of volunteer whole blood, platelet function at low ranges of platelet count and hematocrit levels was assessed on MEA for four agonists and for PFA-100 in two cartridges. Using (multiple) regression analysis, 95% reference intervals were computed for these low ranges. Low platelet counts affected MEA in a positive correlation (all agonists showed r 2 ≥ 0.75) and PFA-100 in an inverse correlation (closure times were prolonged with lower platelet counts). Lowered hematocrit did not affect MEA testing, except for arachidonic acid activation (ASPI), which showed a weak positive correlation (r 2 = 0.14). Closure time on PFA-100 testing was inversely correlated with hematocrit for both cartridges. Regression analysis revealed different 95% reference intervals in comparison with originally established intervals for both MEA and PFA-100 in low platelet or hematocrit conditions. Multiple regression analysis of ASPI and both tests on the PFA-100 for combined low platelet and hematocrit conditions revealed that only PFA-100 testing should be adjusted for both thrombocytopenia and anemia. 95% reference intervals were calculated using multiple regression analysis. However, coefficients of determination of PFA-100 were poor, and some variance remained unexplained. Thus, in this pilot study using (multiple) regression analysis, we could establish reference intervals of platelet function in anemia and thrombocytopenia conditions on PFA-100 and in thrombocytopenia conditions on MEA.

  18. Tularosa Basin Play Fairway Analysis Data and Models

    DOE Data Explorer

    Nash, Greg

    2017-07-11

    This submission includes raster datasets for each layer of evidence used for weights of evidence analysis as well as the deterministic play fairway analysis (PFA). Data representative of heat, permeability and groundwater comprises some of the raster datasets. Additionally, the final deterministic PFA model is provided along with a certainty model. All of these datasets are best used with an ArcGIS software package, specifically Spatial Data Modeler.

  19. Risk Factor Analysis in Low-Temperature Geothermal Play Fairway Analysis for the Appalachian Basin (GPFA-AB)

    DOE Data Explorer

    Teresa E. Jordan

    2015-09-30

    This submission contains information used to compute the risk factors for the GPFA-AB project (DE-EE0006726). The risk factors are natural reservoir quality, thermal resource quality, potential for induced seismicity, and utilization. The methods used to combine the risk factors included taking the product, sum, and minimum of the four risk factors. The files are divided into images, rasters, shapefiles, and supporting information. The image files show what the raster and shapefiles should look like. The raster files contain the input risk factors, calculation of the scaled risk factors, and calculation of the combined risk factors. The shapefiles include definition of the fairways, definition of the US Census Places, the center of the raster cells, and locations of industries. Supporting information contains details of the calculations or processing used in generating the files. An image of the raster will have the same name except *.png as the file ending instead of *.tif. Images with “fairways” or “industries” added to the name are composed of a raster with the relevant shapefile added. The file About_GPFA-AB_Phase1RiskAnalysisTask5DataUpload.pdf contains information the citation, special use considerations, authorship, etc. More details on each file are given in the spreadsheet “list_of_contents.csv” in the folder “SupportingInfo”. Code used to calculate values is available at https://github.com/calvinwhealton/geothermal_pfa under the folder “combining_metrics”.

  20. Infant feeding practices and reported food allergies at 6 years of age.

    PubMed

    Luccioli, Stefano; Zhang, Yuanting; Verrill, Linda; Ramos-Valle, Moraima; Kwegyir-Afful, Ernest

    2014-09-01

    The goal of this study was to identify the frequency of physician-diagnosed food allergies among 6-year-old US children and study the impact of exclusive breastfeeding and complementary food introduction on this frequency. Data were analyzed from children who participated in the Infant Feeding Practices Study II Year 6 Follow-Up Study (Y6FU). Children with probable food allergy (pFA) were defined as children with report of physician-diagnosed food allergy at age 6 years. Subgroups of pFA included children who were not diagnosed before 1 year of age (new pFA) and those with atopic risk factors (high risk). Prevalence of total pFA in the Y6FU was 6.34%. The majority of these children had new pFA and high-risk factors. Higher maternal education, higher family income, family history of food allergy, and reported eczema before 1 year of age were significantly associated with higher odds of total or new pFA. Exclusive breastfeeding duration and timing of complementary food introduction were not significantly associated with total pFA. However, exclusive breastfeeding of ≥4 months compared with no breastfeeding was marginally associated with lower odds of new pFA (adjusted odds ratio: 0.51; P = .07); this effect was not observed with high-risk children. Analysis of infant and maternal variables in the Y6FU cohort of US children revealed that socioeconomic and atopic factors were the main predictors of pFA at age 6 years. Exclusive breastfeeding of ≥4 months may have a preventive effect on development of pFA after 1 year of age in non high-risk children. Copyright © 2014 by the American Academy of Pediatrics.

  1. Food sources of arachidonic acid (PFA 20:4), listed in descending order by percentages of their contribution to intake, based on data from the National Health and Nutrition Examination Survey 2005-2006

    Cancer.gov

    Food sources of arachidonic acid (PFA 20:4), listed in descending order by percentages of their contribution to intake, based on data from the National Health and Nutrition Examination Survey 2005-2006

  2. Food sources of alpha-linolenic acid (PFA 18:3), listed in descending order by percentages of their contribution to intake, based on data from the National Health and Nutrition Examination Survey 2005-2006

    Cancer.gov

    Food sources of alpha-linolenic acid (PFA 18:3), listed in descending order by percentages of their contribution to intake, based on data from the National Health and Nutrition Examination Survey 2005-2006

  3. Electrostatically Driven Large Aperture Micro-Mirror Actuator Assemblies for High Fill-Factor, Agile Optical Phase Arrays

    DTIC Science & Technology

    2015-06-18

    platform assembly 2, with micro-mirror platform deflection, measured on actuation side ( PFa ) and side opposite actuation (PFo...beam micro-mirror platform assembly 1; micro-mirror platform deflection, measured on actuation side ( PFa ) and side opposite actuation (PFo...side ( PFa ) and side opposite actuation (PFo) ........................................................ 106 xiv Figure 73: Graph of measured 10-beam

  4. Patellofemoral arthroplasty conversion to total knee arthroplasty: Retrieval analysis and clinical correlation.

    PubMed

    Christ, Alexander B; Baral, Elexis; Koch, Chelsea; Shubin Stein, Beth E; Gonzalez Della Valle, Alejandro; Strickland, Sabrina M

    2017-10-01

    Patellofemoral arthroplasty (PFA) can be a successful, bone-sparing treatment for isolated patellofemoral arthritis. However, progression of tibio-femoral arthritis or incorrect indications may predispose patients to early conversion to total knee arthroplasty (TKA). The purpose of this study was to review the clinical cases and perform retrieval analysis of PFA conversions to TKA at our institution. Twenty one patellofemoral arthroplasties in 18 patients that were converted to TKA were identified through our implant retrieval registry. Sixteen implants were available for review by biomechanical engineers, who recorded surface markings, wear patterns, and integrity of fixation. Patient charts were reviewed and time to conversion, tourniquet time, conversion implant, additional surgeries, infections, and Kellgren & Lawrence grade of the tibio-femoral joint on pre-operative radiographs were recorded. PFAs converted to TKAs at our institution were implanted for an average of 2.7years. The most common reason for conversion was pain, but most patients had significant tibio-femoral arthritis, as indicated by an average Kellgren & Lawrence grade of 2.6. The average tourniquet time for these conversions was 67min. These patients underwent an average of one additional surgery per PFA converted, and the infection rate of these conversions was approximately 14%. Success of PFA depends upon correct patient selection rather than implant failure or wear. Conversion of PFA to TKA is technically similar to primary TKA, with similar post-operative pain relief and range of motion. However, infection rates and complications requiring further surgery are more consistent with results seen in revision TKA. IV. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Psychological first aid following trauma: implementation and evaluation framework for high-risk organizations.

    PubMed

    Forbes, David; Lewis, Virginia; Varker, Tracey; Phelps, Andrea; O'Donnell, Meaghan; Wade, Darryl J; Ruzek, Josef I; Watson, Patricia; Bryant, Richard A; Creamer, Mark

    2011-01-01

    International clinical practice guidelines for the management of psychological trauma recommend Psychological First Aid (PFA) as an early intervention for survivors of potentially traumatic events. These recommendations are consensus-based, and there is little published evidence assessing the effectiveness of PFA. This is not surprising given the nature of the intervention and the complicating factors involved in any evaluation of PFA. There is, nevertheless, an urgent need for stronger evidence evaluating its effectiveness. The current paper posits that the implementation and evaluation of PFA within high risk organizational settings is an ideal place to start. The paper provides a framework for a phasic approach to implementing PFA within such settings and presents a model for evaluating its effectiveness using a logic- or theory-based approach which considers both pre-event and post-event factors. Phases 1 and 2 of the PFA model are pre-event actions, and phases 3 and 4 are post-event actions. It is hoped that by using the Phased PFA model and evaluation method proposed in this paper, future researchers will begin to undertake the important task of building the evidence about the most effective approach to providing PFA in high risk organizational and community disaster settings.

  6. Waveforms for Active Sensing: Optical Waveform Design and Analysis for Ballistic Imaging Through Turbid Media

    DTIC Science & Technology

    2008-04-04

    Poisson process, the probabilities of false alarm PFA and detection PD are computed as PFA P k1 N yk 0 k 1 eNXeNXek k! 1...character- istics (ROC) (PD versus PFA ) curves for detecting opaque objects in heavy fog, considering a detector with Xe 20 and a laser power as in...objects in this scattering me- dium up to a distance of 30 MFPs. Figure 4(b) shows the system performance curves by fixing the false alarm rate PFA at

  7. Multiple electrode whole blood aggregometry, PFA-100, and in vivo bleeding time for the point-of-care assessment of aspirin-induced platelet dysfunction in the preoperative setting.

    PubMed

    Jámbor, Csilla; von Pape, Klaus-Werner; Spannagl, Michael; Dietrich, Wulf; Giebl, Andreas; Weisser, Heike

    2011-07-01

    Acquired platelet dysfunction due to aspirin ingestion may increase bleeding tendency during surgery. Thus, we examined the diagnostic accuracy of in vivo bleeding time (BT) and 2 platelet function assays for the preoperative assessment of a residual antiplatelet effect in patients treated with aspirin. Consecutive patients scheduled for surgery were prospectively enrolled in this study. The patients' last aspirin ingestion had occurred within the previous 48 hours before blood sampling in the "full aspirin effect" group, between 48 and 96 hours before in the "variable aspirin effect" group, and >96 hours before in the "recovered aspirin effect" group. The control group had not taken any aspirin. Multiple electrode aggregometry, platelet function analyzer (PFA)-100, and in vivo BT were performed to assess the effects of aspirin. One-way analysis of variance on ranks with a post hoc multiple-comparison procedure (Dunn) was used to detect differences among the groups. Categorical data were compared using the z test. Receiver operating characteristic (ROC) curves were created to determine the diagnostic accuracy of the platelet function assays investigated. The area under the ROC curve (AUC), sensitivity, and specificity of the assays were calculated. The level of statistical significance was set at P < 0.05. Three hundred ninety-four patients were included in the analysis (133 control and 261 aspirin-treated patients). All 3 methods were able to detect the antiplatelet effect of aspirin in the full aspirin effect group. Furthermore, no difference in the measurement values between the recovered aspirin effect and control group was found, irrespective of the assay performed. Measurement values in the variable aspirin effect group were different from those of the control group in the ASPItest using multiple electrode aggregometry and COL-EPI using PFA-100 but not in BT. ROC analysis showed the highest diagnostic accuracy in excluding the residual aspirin effect in the

  8. Does bottle type and acid-washing influence trace element analyses by ICP-MS on water samples? A test covering 62 elements and four bottle types: high density polyethene (HDPE), polypropene (PP), fluorinated ethene propene copolymer (FEP) and perfluoroalkoxy polymer (PFA).

    PubMed

    Reimann, C; Siewers, U; Skarphagen, H; Banks, D

    1999-10-01

    Groundwater samples from 15 boreholes in crystalline bedrock aquifers in South Norway (Oslo area) have been collected in parallel in five different clear plastic bottle types (high density polyethene [HDPE], polypropene [PP, two manufacturers], fluorinated ethene propene copolymer [FEP] and perfluoroalkoxy polymer [PFA]. In the cases of polyethene and polypropene, parallel samples have been collected in factory-new (unwashed) bottles and acid-washed factory-new bottles. Samples have been analysed by ICP-MS techniques for a wide range of inorganic elements down to the ppt (ng/l) range. It was found that acid-washing of factory-new flasks had no clear systematic beneficial effect on analytical result. On the contrary, for the PP-bottles concentrations of Pb and Sn were clearly elevated in the acid-washed bottles. Likewise, for the vast majority of elements, bottle type was of no importance for analytical result. For six elements (Al, Cr, Hf, Hg, Pb and Sn) some systematic differences for one or more bottle types could be tentatively discerned, but in no case was the discrepancy of major cause for concern. The most pronounced effect was for Cr, with clearly elevated concentrations returned from the samples collected in HDPE bottles, regardless of acid-washing or not. For the above six elements, FEP or PFA bottles seemed to be marginally preferable to PP and HDPE. In general, cheap HDPE, factory new, unwashed flasks are suitable for sampling waters for ICP-MS ultra-trace analysis of the elements tested.

  9. SE Great Basin Play Fairway Analysis

    DOE Data Explorer

    Adam Brandt

    2015-11-15

    Within this submission are multiple .tif images with accompanying metadata of magnetotelluric conductor occurrence, fault critical stress composite risk segment (CRS), permeability CRS, Quaternary mafic extrusions, Quaternary fault density, and Quaternary rhyolite maps. Each of these contributed to a final play fairway analysis (PFA) for the SE Great Basin study area.

  10. Review of the probabilistic failure analysis methodology and other probabilistic approaches for application in aerospace structural design

    NASA Technical Reports Server (NTRS)

    Townsend, J.; Meyers, C.; Ortega, R.; Peck, J.; Rheinfurth, M.; Weinstock, B.

    1993-01-01

    Probabilistic structural analyses and design methods are steadily gaining acceptance within the aerospace industry. The safety factor approach to design has long been the industry standard, and it is believed by many to be overly conservative and thus, costly. A probabilistic approach to design may offer substantial cost savings. This report summarizes several probabilistic approaches: the probabilistic failure analysis (PFA) methodology developed by Jet Propulsion Laboratory, fast probability integration (FPI) methods, the NESSUS finite element code, and response surface methods. Example problems are provided to help identify the advantages and disadvantages of each method.

  11. Towards successful Dissemination of Psychological First Aid: a study of provider training preferences.

    PubMed

    Hambrick, Erin P; Rubens, Sonia L; Vernberg, Eric M; Jacobs, Anne K; Kanine, Rebecca M

    2014-04-01

    Dissemination of Psychological First Aid (PFA) is challenging considering the complex nature of disaster response and the various disaster mental health (DMH) trainings available. To understand challenges to dissemination in community mental health centers (CMHCs), interviews were conducted with nine DMH providers associated with CMHCs. Consensual qualitative analysis was used to analyze data. Interviews were targeted toward understanding organizational infrastructure, DMH training requirements, and training needs. Results clarified challenges to DMH training in CMHCs and factors that may promote buy-in for trainings. For example, resources are limited and thus allocated for state and federal training requirements. Therefore, including PFA in these requirements could promote adoption. Additionally, a variety of training approaches that differ in content, style, and length would be useful. To conclude, a conceptual model for ways to promote buy-in for the PFA Guide is proposed.

  12. Washington Geothermal Play Fairway Analysis Data From Potential Field Studies

    DOE Data Explorer

    Anderson, Megan; Ritzinger, Brent; Glen, Jonathan; Schermerhorn, William

    2017-12-20

    A recent study which adapts play fairway analysis (PFA) methodology to assess geothermal potential was conducted at three locations (Mount Baker, Mount St. Helens seismic zone, and Wind River valley) along the Washington Cascade Range (Forson et al. 2017). Potential field (gravity and magnetic) methods which can detect subsurface contrasts in physical properties, provides a means for mapping and modeling subsurface geology and structure. As part of the WA-Cascade PFA project, we performed potential field studies by collecting high-resolution gravity and ground-magnetic data, and rock property measurements to (1) identify and constrain fault geometries (2) constrain subsurface lithologic distribution (3) study fault interactions (4) identify areas favorable to hydrothermal flow, and ultimately (5) guide future geothermal exploration at each location.

  13. An improved approach for flight readiness certification: Methodology for failure risk assessment and application examples, volume 1

    NASA Technical Reports Server (NTRS)

    Moore, N. R.; Ebbeler, D. H.; Newlin, L. E.; Sutharshana, S.; Creager, M.

    1992-01-01

    An improved methodology for quantitatively evaluating failure risk of spaceflight systems to assess flight readiness and identify risk control measures is presented. This methodology, called Probabilistic Failure Assessment (PFA), combines operating experience from tests and flights with engineering analysis to estimate failure risk. The PFA methodology is of particular value when information on which to base an assessment of failure risk, including test experience and knowledge of parameters used in engineering analyses of failure phenomena, is expensive or difficult to acquire. The PFA methodology is a prescribed statistical structure in which engineering analysis models that characterize failure phenomena are used conjointly with uncertainties about analysis parameters and/or modeling accuracy to estimate failure probability distributions for specific failure modes. These distributions can then be modified, by means of statistical procedures of the PFA methodology, to reflect any test or flight experience. Conventional engineering analysis models currently employed for design of failure prediction are used in this methodology. The PFA methodology is described and examples of its application are presented. Conventional approaches to failure risk evaluation for spaceflight systems are discussed, and the rationale for the approach taken in the PFA methodology is presented. The statistical methods, engineering models, and computer software used in fatigue failure mode applications are thoroughly documented.

  14. An improved approach for flight readiness certification: Methodology for failure risk assessment and application examples. Volume 3: Structure and listing of programs

    NASA Technical Reports Server (NTRS)

    Moore, N. R.; Ebbeler, D. H.; Newlin, L. E.; Sutharshana, S.; Creager, M.

    1992-01-01

    An improved methodology for quantitatively evaluating failure risk of spaceflight systems to assess flight readiness and identify risk control measures is presented. This methodology, called Probabilistic Failure Assessment (PFA), combines operating experience from tests and flights with engineering analysis to estimate failure risk. The PFA methodology is of particular value when information on which to base an assessment of failure risk, including test experience and knowledge of parameters used in engineering analyses of failure phenomena, is expensive or difficult to acquire. The PFA methodology is a prescribed statistical structure in which engineering analysis models that characterize failure phenomena are used conjointly with uncertainties about analysis parameters and/or modeling accuracy to estimate failure probability distributions for specific failure modes. These distributions can then be modified, by means of statistical procedures of the PFA methodology, to reflect any test or flight experience. Conventional engineering analysis models currently employed for design of failure prediction are used in this methodology. The PFA methodology is described and examples of its application are presented. Conventional approaches to failure risk evaluation for spaceflight systems are discussed, and the rationale for the approach taken in the PFA methodology is presented. The statistical methods, engineering models, and computer software used in fatigue failure mode applications are thoroughly documented.

  15. An improved approach for flight readiness certification: Methodology for failure risk assessment and application examples. Volume 2: Software documentation

    NASA Technical Reports Server (NTRS)

    Moore, N. R.; Ebbeler, D. H.; Newlin, L. E.; Sutharshana, S.; Creager, M.

    1992-01-01

    An improved methodology for quantitatively evaluating failure risk of spaceflight systems to assess flight readiness and identify risk control measures is presented. This methodology, called Probabilistic Failure Assessment (PFA), combines operating experience from tests and flights with engineering analysis to estimate failure risk. The PFA methodology is of particular value when information on which to base an assessment of failure risk, including test experience and knowledge of parameters used in engineering analyses of failure phenomena, is expensive or difficult to acquire. The PFA methodology is a prescribed statistical structure in which engineering analysis models that characterize failure phenomena are used conjointly with uncertainties about analysis parameters and/or modeling accuracy to estimate failure probability distributions for specific failure modes, These distributions can then be modified, by means of statistical procedures of the PFA methodology, to reflect any test or flight experience. Conventional engineering analysis models currently employed for design of failure prediction are used in this methodology. The PFA methodology is described and examples of its application are presented. Conventional approaches to failure risk evaluation for spaceflight systems are discussed, and the rationale for the approach taken in the PFA methodology is presented. The statistical methods, engineering models, and computer software used in fatigue failure mode applications are thoroughly documented.

  16. Accounting for Slipping and Other False Negatives in Logistic Models of Student Learning

    ERIC Educational Resources Information Center

    MacLellan, Christopher J.; Liu, Ran; Koedinger, Kenneth R.

    2015-01-01

    Additive Factors Model (AFM) and Performance Factors Analysis (PFA) are two popular models of student learning that employ logistic regression to estimate parameters and predict performance. This is in contrast to Bayesian Knowledge Tracing (BKT) which uses a Hidden Markov Model formalism. While all three models tend to make similar predictions,…

  17. Multifunctional green nanostructured composites: preparation and characterization

    NASA Astrophysics Data System (ADS)

    Stieven Montagna, Larissa; Sizuka Oishi, Silvia; Faria Diniz, Milton; Larissa do Amaral Montanheiro, Thaís; Santos da Silva, Fábio; Passador, Fábio Roberto; Cerqueira Rezende, Mirabel

    2018-05-01

    The present research had as main purpose to develop and characterize multifunctional green nanocomposites based on poly(furfuryl alcohol) resin (PFA bioresin), derived from sugarcane bagasse reinforced with different contents of graphite nanosheets (GNS) (0.5, 1.0, 1.5 and 2.0 wt%) which were dispersed in PFA bioresin using an ultrasonic processor. The mixture was poured into silicone molds and cured at room temperature during 24 h followed by a post-cure at preheated oven in cycles of different temperatures. TEM analysis of GNS showed this filler consist of ultrathin and layered sheets. SEM micrographs of the cryogenic fracture of the nanocomposite presented the good interfacial adhesion between PFA bioresin and GNS. Moreover, upon GNS addition in the PFA bioresin, PFA/GNS nanocomposites demonstrated superior mechanical performance and better electrical conductivity than neat PFA bioresin.

  18. Oregon Cascades Play Fairway Analysis: Raster Datasets and Models

    DOE Data Explorer

    Adam Brandt

    2015-11-15

    This submission includes maps of the spatial distribution of basaltic, and felsic rocks in the Oregon Cascades. It also includes a final Play Fairway Analysis (PFA) model, with the heat and permeability composite risk segments (CRS) supplied separately. Metadata for each raster dataset can be found within the zip files, in the TIF images

  19. Final Research Performance Report - Small Molecular Associative Carbon Dioxide (CO 2) Thickeners for Improved Mobility Control

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

    Enick, Robert M.

    conducted at Special Core Analysis Laboratories, Inc., (SCAL) in Midland, TX, where the ability for PFA to reduce CO 2 mobility in a core was then tested. During the beginning of these tests, the PFA polymer was then shown to impart reasonable improvements in mobility control during the SCAL core tests; as the CO 2-PFA solution displaced CO 2 from the core at a constant volumetric flow rate, the pressure drop increased as expected. However, as the test progressed, there was clear and surprising evidence of dramatic reductions in core permeability due to PFA adsorption, especially for sandstones. For example, as the CO 2-PFA solution displaced pure CO 2 from sandstone and limestone cores, the pressure drop increased by factors of multiple hundreds to over a thousand. It was subsequently demonstrated that the PFA injected into the core either (a) adsorbed strongly and irreversibly onto the rock surfaces, (b) deposited/precipitated within the rock, thereby blocking pores in a manner that could be dislodged by large changes in flow rate or flow direction, or (c) remained in solution and passed completely through the core. The loss of PFA to the porous media and the unacceptably large increases in pressure drop both indicated that PFA was inappropriate for CO 2 EOR mobility control, where thickener adsorption must be minimized and mobility reductions of only 10-100-fold are typically required. However, we realized that because the CO 2-PFA solution could greatly reduce the permeability of porous media, it could serve as a near wellbore conformance control agent for blocking “thief zones”, where adsorption is acceptable and dramatic increases in pressure drop are desirable. These effects were more dramatic for sandstone than for limestone. Therefore, these PFA fluoroacrylate polymers can serve as a CO 2-soluble conformance control agent for CO 2-EOR, especially in sandstone formations. This injection of a single phase solution of CO 2-PFA for permeability reduction is (to the

  20. Tularosa Basin Play Fairway Analysis: Methodology Flow Charts

    DOE Data Explorer

    Adam Brandt

    2015-11-15

    These images show the comprehensive methodology used for creation of a Play Fairway Analysis to explore the geothermal resource potential of the Tularosa Basin, New Mexico. The deterministic methodology was originated by the petroleum industry, but was custom-modified to function as a knowledge-based geothermal exploration tool. The stochastic PFA flow chart uses weights of evidence, and is data-driven.

  1. Platelet function analysis with two different doses of aspirin.

    PubMed

    Aydinalp, Alp; Atar, Ilyas; Altin, Cihan; Gülmez, Oykü; Atar, Asli; Açikel, Sadik; Bozbaş, Hüseyin; Yildirir, Aylin; Müderrisoğlu, Haldun

    2010-06-01

    We aimed to compare the level of platelet inhibition using the platelet function analyzer (PFA)-100 in patients receiving low and medium doses of aspirin. On a prospective basis, 159 cardiology outpatients (83 men, 76 women; mean age 60.9 ± 9.9 years) taking 100 mg/day or 300 mg/day aspirin at least for the previous 15 days were included. Of these, 79 patients (50%) were on 100 mg and 80 patients (50.3%) were on 300 mg aspirin treatment. Blood samples were collected between 09:30 and 11:00 hours in the morning. Platelet reactivity was measured with the PFA-100 system. Incomplete platelet inhibition was defined as a normal collagen/epinephrine closure time (< 165 sec) despite aspirin treatment. Baseline clinical and laboratory characteristics of the patient groups taking 100 mg or 300 mg aspirin were similar. The overall prevalence of incomplete platelet inhibition was 22% (35 patients). The prevalence of incomplete platelet inhibition was significantly higher in patients treated with 100 mg of aspirin (n = 24/79, 30.4%) compared with those treated with 300 mg of aspirin (n = 11/80, 13.8%) (p = 0.013). In univariate analysis, female sex (p = 0.002) and aspirin dose (p = 0.013) were significantly correlated with incomplete platelet inhibition. In multivariate analysis, female sex (OR: 0.99; 95% CI 0.9913-0.9994; p = 0.025) and aspirin dose (OR: 3.38; 95% CI 1.4774-7.7469; p = 0.003) were found as independent factors predictive of incomplete platelet inhibition. Our findings suggest that treatment with higher doses of aspirin can reduce incomplete platelet inhibition especially in female patients.

  2. Patellofemoral Arthroplasty: Current Concepts and Review of the Literature

    PubMed Central

    Pisanu, Gabriele; Rosso, Federica; Bertolo, Corrado; Dettoni, Federico; Blonna, Davide; Bonasia, Davide Edoardo; Rossi, Roberto

    2017-01-01

    Patellofemoral osteoarthritis (PFOA) can be associated with anterior knee pain, stiffness, and functional impairment. Some authors report that PFOA affects approximately 9% of patients older than 40 years with a greater prevalence in females. Etiology of PFOA is multifactorial and is related to the presence of abnormal stresses at the PF joint due to knee- and patient-related factors. The need for a joint preserving treatment by isolated replacement of the injured compartment of the knee led to the development of PF arthroplasty (PFA). When a correct PF replacement is performed, PFA preserves physiologic tibiofemoral joint, thus allowing patients for a rapid recovery with a high satisfaction. The outcomes for PFA are quite variable with a trend toward good to excellent results, mainly owing to the improvement in surgical techniques, patient selection, and implant design. The development of the second generation of PFA improved the outcomes, which is attributed to the different trochlear designs. Recently, encouraging results have been provided by the association of PFA and unicompartmental knee arthroplasty (UKA). In many studies, the main cause of PFA failure is progression of tibiofemoral OA. The aim of this brief review of literature is to summarize the clinical features, indications and contraindications, surgical techniques, complications, and outcomes of PFA. PMID:29270562

  3. Phylogenetic and genetic linkage between novel atypical dual-specificity phosphatases from non-metazoan organisms.

    PubMed

    Romá-Mateo, Carlos; Sacristán-Reviriego, Almudena; Beresford, Nicola J; Caparrós-Martín, José Antonio; Culiáñez-Macià, Francisco A; Martín, Humberto; Molina, María; Tabernero, Lydia; Pulido, Rafael

    2011-04-01

    Dual-specificity phosphatases (DSPs) constitute a large protein tyrosine phosphatase (PTP) family, with examples in distant evolutive phyla. PFA-DSPs (Plant and Fungi Atypical DSPs) are a group of atypical DSPs present in plants, fungi, kinetoplastids, and slime molds, the members of which share structural similarity with atypical- and lipid phosphatase DSPs from mammals. The analysis of the PFA-DSPs from the plant Arabidopsis thaliana (AtPFA-DSPs) showed differential tissue mRNA expression, substrate specificity, and catalytic activity for these proteins, suggesting different functional roles among plant PFA-DSPs. Bioinformatic analysis revealed the existence of novel PFA-DSP-related proteins in fungi (Oca1, Oca2, Oca4 and Oca6 in Saccharomyces cerevisiae) and protozoa, which were segregated from plant PFA-DSPs. The closest yeast homolog for these proteins was the PFA-DSP from S. cerevisiae ScPFA-DSP1/Siw14/Oca3. Oca1, Oca2, Siw14/Oca3, Oca4, and Oca6 were involved in the yeast response to caffeine and rapamycin stresses. Siw14/Oca3 was an active phosphatase in vitro, whereas no phosphatase activity could be detected for Oca1. Remarkably, overexpression of Siw14/Oca3 suppressed the caffeine sensitivity of oca1, oca2, oca4, and oca6 deleted strains, indicating a genetic linkage and suggesting a functional relationship for these proteins. Functional studies on mutations targeting putative catalytic residues from the A. thaliana AtPFA-DSP1/At1g05000 protein indicated the absence of canonical amino acids acting as the general acid/base in the phosphor-ester hydrolysis, which suggests a specific mechanism of reaction for PFA-DSPs and related enzymes. Our studies demonstrate the existence of novel phosphatase protein families in fungi and protozoa, with active and inactive enzymes linked in common signaling pathways. This illustrates the catalytic and functional complexity of the expanding family of atypical dual-specificity phosphatases in non-metazoans, including

  4. Environmental barrier coating (EBC) durability modeling using a progressive failure analysis approach

    NASA Astrophysics Data System (ADS)

    Abdul-Aziz, Ali; Abumeri, Galib; Troha, William; Bhatt, Ramakrishna T.; Grady, Joseph E.; Zhu, D.

    2012-04-01

    Ceramic matrix composites (CMCs) are getting the attention of most engine manufacturers and aerospace firms for turbine engine and other related applications. This is because of their potential weight advantage and performance benefits. As a protecting guard for these materials, a highly specialized form of environmental barrier coating (EBC) is being developed and explored for high temperature applications that are greater than 1100 °C1,2. The EBCs are typically a multilayer of coatings and are on the order of hundreds of microns thick. CMCs are generally porous materials and this feature is somewhat beneficial since it allows some desirable infiltration of the EBC. Their degradation usually includes coating interface oxidation as opposed to moisture induced matrix degradation which is generally seen at a higher temperature. A variety of factors such as residual stresses, coating process related flaws, and casting conditions may influence the strength of degradation. The cause of such defects which cause cracking and other damage is that not much energy is absorbed during fracture of these materials. Therefore, an understanding of the issues that control crack deflection and propagation along interfaces is needed to maximize the energy dissipation capabilities of layered ceramics. Thus, evaluating components and subcomponents made out of CMCs under gas turbine engine conditions is suggested to demonstrate that these material will perform as expected and required under these aggressive environmental circumstances. Progressive failure analysis (PFA) is applied to assess the damage growth of the coating under combined thermal and mechanical loading conditions. The PFA evaluation is carried out using a full-scale finite element model to account for the average material failure at the microscopic or macroscopic levels. The PFA life prediction evaluation identified the root cause for damage initiation and propagation. It indicated that delamination type damage

  5. An improved approach for flight readiness certification: Probabilistic models for flaw propagation and turbine blade failure. Volume 1: Methodology and applications

    NASA Technical Reports Server (NTRS)

    Moore, N. R.; Ebbeler, D. H.; Newlin, L. E.; Sutharshana, S.; Creager, M.

    1992-01-01

    An improved methodology for quantitatively evaluating failure risk of spaceflight systems to assess flight readiness and identify risk control measures is presented. This methodology, called Probabilistic Failure Assessment (PFA), combines operating experience from tests and flights with analytical modeling of failure phenomena to estimate failure risk. The PFA methodology is of particular value when information on which to base an assessment of failure risk, including test experience and knowledge of parameters used in analytical modeling, is expensive or difficult to acquire. The PFA methodology is a prescribed statistical structure in which analytical models that characterize failure phenomena are used conjointly with uncertainties about analysis parameters and/or modeling accuracy to estimate failure probability distributions for specific failure modes. These distributions can then be modified, by means of statistical procedures of the PFA methodology, to reflect any test or flight experience. State-of-the-art analytical models currently employed for designs failure prediction, or performance analysis are used in this methodology. The rationale for the statistical approach taken in the PFA methodology is discussed, the PFA methodology is described, and examples of its application to structural failure modes are presented. The engineering models and computer software used in fatigue crack growth and fatigue crack initiation applications are thoroughly documented.

  6. An improved approach for flight readiness certification: Probabilistic models for flaw propagation and turbine blade failure. Volume 2: Software documentation

    NASA Technical Reports Server (NTRS)

    Moore, N. R.; Ebbeler, D. H.; Newlin, L. E.; Sutharshana, S.; Creager, M.

    1992-01-01

    An improved methodology for quantitatively evaluating failure risk of spaceflights systems to assess flight readiness and identify risk control measures is presented. This methodology, called Probabilistic Failure Assessment (PFA), combines operating experience from tests and flights with analytical modeling of failure phenomena to estimate failure risk. The PFA methodology is of particular value when information on which to base an assessment of failure risk, including test experience and knowledge of parameters used in analytical modeling, is expensive or difficult to acquire. The PFA methodology is a prescribed statistical structure in which analytical models that characterize failure phenomena are used conjointly with uncertainties about analysis parameters and/or modeling accuracy to estimate failure probability distributions for specific failure modes. These distributions can then be modified, by means of statistical procedures of the PFA methodology, to reflect any test or flight experience. State-of-the-art analytical models currently employed for design, failure prediction, or performance analysis are used in this methodology. The rationale for the statistical approach taken in the PFA methodology is discussed, the PFA methodology is described, and examples of its application to structural failure modes are presented. The engineering models and computer software used in fatigue crack growth and fatigue crack initiation applications are thoroughly documented.

  7. Factor Analysis via Components Analysis

    ERIC Educational Resources Information Center

    Bentler, Peter M.; de Leeuw, Jan

    2011-01-01

    When the factor analysis model holds, component loadings are linear combinations of factor loadings, and vice versa. This interrelation permits us to define new optimization criteria and estimation methods for exploratory factor analysis. Although this article is primarily conceptual in nature, an illustrative example and a small simulation show…

  8. An Investigation into the Gravity Current Aspects of a Cold Air Outbreak Using Variational Analysis Techniques

    DTIC Science & Technology

    1988-01-01

    the motiorn of the front- Behind the front betwueen Peorias (PIA) and Salem (510) 0 is directly in phase with Ca uwhich enhmwves the deuealapment omf...4ower coi ij. 77 (A.k, 1 -A~k)/Zp A PFA PC - (*A-)/pAPAP +(4)cOk.1 4 ) Ok...4j)llAPC -. kk,/2 Mc-Tok = 0 For k=3,7 uphicmh simplifies tv, Futr k=3,7...EQN 7), RAk+A𔃼rA PFA Ptc*-~k-’PA PB&~ PC4(+ oyk*17+ k.1>.OA PC-Ta-k] 112- A PFA PC + 114P A pi-APC + 1/2c- Fcr k=Z EQN 8), Xk=[Xk+./2PAPFAPC

  9. Transforming Graph Data for Statistical Relational Learning

    DTIC Science & Technology

    2012-10-01

    Jordan, 2003), PLSA (Hofmann, 1999), ? Classification via RMN (Taskar et al., 2003) or SVM (Hasan, Chaoji, Salem , & Zaki, 2006) ? Hierarchical...dimensionality reduction methods such as Principal 407 Rossi, McDowell, Aha, & Neville Component Analysis (PCA), Principal Factor Analysis ( PFA ), and...clustering algorithm. Journal of the Royal Statistical Society. Series C, Applied statistics, 28, 100–108. Hasan, M. A., Chaoji, V., Salem , S., & Zaki, M

  10. Immunohistochemical analysis of H3K27me3 demonstrates global reduction in group-A childhood posterior fossa ependymoma and is a powerful predictor of outcome.

    PubMed

    Panwalkar, Pooja; Clark, Jonathan; Ramaswamy, Vijay; Hawes, Debra; Yang, Fusheng; Dunham, Christopher; Yip, Stephen; Hukin, Juliette; Sun, Yilun; Schipper, Matthew J; Chavez, Lukas; Margol, Ashley; Pekmezci, Melike; Chung, Chan; Banda, Adam; Bayliss, Jill M; Curry, Sarah J; Santi, Mariarita; Rodriguez, Fausto J; Snuderl, Matija; Karajannis, Matthias A; Saratsis, Amanda M; Horbinski, Craig M; Carret, Anne-Sophie; Wilson, Beverly; Johnston, Donna; Lafay-Cousin, Lucie; Zelcer, Shayna; Eisenstat, David; Silva, Marianna; Scheinemann, Katrin; Jabado, Nada; McNeely, P Daniel; Kool, Marcel; Pfister, Stefan M; Taylor, Michael D; Hawkins, Cynthia; Korshunov, Andrey; Judkins, Alexander R; Venneti, Sriram

    2017-11-01

    Posterior fossa ependymomas (EPN_PF) in children comprise two morphologically identical, but biologically distinct tumor entities. Group-A (EPN_PFA) tumors have a poor prognosis and require intensive therapy. In contrast, group-B tumors (EPN_PFB) exhibit excellent prognosis and the current consensus opinion recommends future clinical trials to test the possibility of treatment de-escalation in these patients. Therefore, distinguishing these two tumor subtypes is critical. EPN_PFA and EPN_PFB can be distinguished based on DNA methylation signatures, but these assays are not routinely available. We have previously shown that a subset of poorly prognostic childhood EPN_PF exhibits global reduction in H3K27me3. Therefore, we set out to determine whether a simple immunohistochemical assay for H3K27me3 could be used to segregate EPN_PFA from EPN_PFB tumors. We assembled a cohort of 230 childhood ependymomas and H3K27me3 immunohistochemistry was assessed as positive or negative in a blinded manner. H3K27me3 staining results were compared with DNA methylation-based subgroup information available in 112 samples [EPN_PFA (n = 72) and EPN_PFB tumors (n = 40)]. H3K27me3 staining was globally reduced in EPN_PFA tumors and immunohistochemistry showed 99% sensitivity and 100% specificity in segregating EPN_PFA from EPN_PFB tumors. Moreover, H3K27me3 immunostaining was sufficient to delineate patients with worse prognosis in two independent, non-overlapping cohorts (n = 133 and n = 97). In conclusion, immunohistochemical evaluation of H3K27me3 global reduction is an economic, easily available and readily adaptable method for defining high-risk EPN_PFA from low-risk posterior fossa EPN_PFB tumors to inform prognosis and to enable the design of future clinical trials.

  11. Factor Analysis and Counseling Research

    ERIC Educational Resources Information Center

    Weiss, David J.

    1970-01-01

    Topics discussed include factor analysis versus cluster analysis, analysis of Q correlation matrices, ipsativity and factor analysis, and tests for the significance of a correlation matrix prior to application of factor analytic techniques. Techniques for factor extraction discussed include principal components, canonical factor analysis, alpha…

  12. Biologic variability and correlation of platelet function testing in healthy dogs.

    PubMed

    Blois, Shauna L; Lang, Sean T; Wood, R Darren; Monteith, Gabrielle

    2015-12-01

    Platelet function tests are influenced by biologic variability, including inter-individual (CVG ) and intra-individual (CVI ), as well as analytic (CVA ) variability. Variability in canine platelet function testing is unknown, but if excessive, would make it difficult to interpret serial results. Additionally, the correlation between platelet function tests is poor in people, but not well described in dogs. The aims were to: (1) identify the effect of variation in preanalytic factors (venipuncture, elapsed time until analysis) on platelet function tests; (2) calculate analytic and biologic variability of adenosine diphosphate (ADP) and arachidonic acid (AA)-induced thromboelastograph platelet mapping (TEG-PM), ADP-, AA-, and collagen-induced whole blood platelet aggregometry (WBA), and collagen/ADP and collagen/epinephrine platelet function analysis (PFA-CADP, PFA-CEPI); and (3) determine the correlation between these variables. In this prospective observational trial, platelet function was measured once every 7 days, for 4 consecutive weeks, in 9 healthy dogs. In addition, CBC, TEG-PM, WBA, and PFA were performed. Overall coefficients of variability ranged from 13.3% to 87.8% for the platelet function tests. Biologic variability was highest for AA-induced maximum amplitude generated during TEG-PM (MAAA; CVG = 95.3%, CVI = 60.8%). Use of population-based reference intervals (RI) was determined appropriate only for PFA-CADP (index of individuality = 10.7). There was poor correlation between most platelet function tests. Use of population-based RI appears inappropriate for most platelet function tests, and tests poorly correlate with one another. Future studies on biologic variability and correlation of platelet function tests should be performed in dogs with platelet dysfunction and those treated with antiplatelet therapy. © 2015 American Society for Veterinary Clinical Pathology.

  13. Failure Analysis in Platelet Molded Composite Systems

    NASA Astrophysics Data System (ADS)

    Kravchenko, Sergii G.

    Long-fiber discontinuous composite systems in the form of chopped prepreg tapes provide an advanced, structural grade, molding compound allowing for fabrication of complex three-dimensional components. Understanding of process-structure-property relationship is essential for application of prerpeg platelet molded components, especially because of their possible irregular disordered heterogeneous morphology. Herein, a structure-property relationship was analyzed in the composite systems of many platelets. Regular and irregular morphologies were considered. Platelet-based systems with more ordered morphology possess superior mechanical performance. While regular morphologies allow for a careful inspection of failure mechanisms derived from the morphological characteristics, irregular morphologies are representative of the composite architectures resulting from uncontrolled deposition and molding with chopped prerpegs. Progressive failure analysis (PFA) was used to study the damaged deformation up to ultimate failure in a platelet-based composite system. Computational damage mechanics approaches were utilized to conduct the PFA. The developed computational models granted understanding of how the composite structure details, meaning the platelet geometry and system morphology (geometrical arrangement and orientation distribution of platelets), define the effective mechanical properties of a platelet-molded composite system, its stiffness, strength and variability in properties.

  14. Thermal behavior of phenol-furfuryl alcohol resin/carbon nanotubes composites

    NASA Astrophysics Data System (ADS)

    Conejo, L. S.; Costa, M. L.; Oishi, S. S.; Botelho, E. C.

    2018-04-01

    Phenol-furfuryl alcohol resins (PFA) are excellent candidates to replace existing thermoset matrices used in obtaining insulating systems or carbon materials, both in its pure form and reinforced with nanoscale structures. This work had as main purpose synthesize and investigate thermal characterization of PFA resin and its nanostructured composites with different concentrations of carbon nanotubes (0, 0.1, 0.5 and 1.0 wt%). The DSC analysis was performed to estimate the specific heat (cp) of the cured samples and thermomechanical analysis to find the linear thermal expansion coefficient (α). From these results, the cp values found for the PFA system was similar to that described in the literature for the phenolic resin. The cp increased with the increase in the CNT concentration in the system up to 0.5%. The coefficient of linear thermal expansion obtained by TMA technique for PFA sample was 33.10‑6/°C which was close to the α value of phenolic resin (40 to 80.10‑6/°C).

  15. Therapeutic Impact of Cytoreductive Surgery and Irradiation of Posterior Fossa Ependymoma in the Molecular Era: A Retrospective Multicohort Analysis

    PubMed Central

    Ramaswamy, Vijay; Hielscher, Thomas; Mack, Stephen C.; Lassaletta, Alvaro; Lin, Tong; Pajtler, Kristian W.; Jones, David T.W.; Luu, Betty; Cavalli, Florence M.G.; Aldape, Kenneth; Remke, Marc; Mynarek, Martin; Rutkowski, Stefan; Gururangan, Sridharan; McLendon, Roger E.; Lipp, Eric S.; Dunham, Christopher; Hukin, Juliette; Eisenstat, David D.; Fulton, Dorcas; van Landeghem, Frank K.H.; Santi, Mariarita; van Veelen, Marie-Lise C.; Van Meir, Erwin G.; Osuka, Satoru; Fan, Xing; Muraszko, Karin M.; Tirapelli, Daniela P.C.; Oba-Shinjo, Sueli M.; Marie, Suely K.N.; Carlotti, Carlos G.; Lee, Ji Yeoun; Rao, Amulya A. Nageswara; Giannini, Caterina; Faria, Claudia C.; Nunes, Sofia; Mora, Jaume; Hamilton, Ronald L.; Hauser, Peter; Jabado, Nada; Petrecca, Kevin; Jung, Shin; Massimi, Luca; Zollo, Massimo; Cinalli, Giuseppe; Bognár, László; Klekner, Almos; Hortobágyi, Tibor; Leary, Sarah; Ermoian, Ralph P.; Olson, James M.; Leonard, Jeffrey R.; Gardner, Corrine; Grajkowska, Wieslawa A.; Chambless, Lola B.; Cain, Jason; Eberhart, Charles G.; Ahsan, Sama; Massimino, Maura; Giangaspero, Felice; Buttarelli, Francesca R.; Packer, Roger J.; Emery, Lyndsey; Yong, William H.; Soto, Horacio; Liau, Linda M.; Everson, Richard; Grossbach, Andrew; Shalaby, Tarek; Grotzer, Michael; Karajannis, Matthias A.; Zagzag, David; Wheeler, Helen; von Hoff, Katja; Alonso, Marta M.; Tuñon, Teresa; Schüller, Ulrich; Zitterbart, Karel; Sterba, Jaroslav; Chan, Jennifer A.; Guzman, Miguel; Elbabaa, Samer K.; Colman, Howard; Dhall, Girish; Fisher, Paul G.; Fouladi, Maryam; Gajjar, Amar; Goldman, Stewart; Hwang, Eugene; Kool, Marcel; Ladha, Harshad; Vera-Bolanos, Elizabeth; Wani, Khalida; Lieberman, Frank; Mikkelsen, Tom; Omuro, Antonio M.; Pollack, Ian F.; Prados, Michael; Robins, H. Ian; Soffietti, Riccardo; Wu, Jing; Metellus, Phillipe; Tabori, Uri; Bartels, Ute; Bouffet, Eric; Hawkins, Cynthia E.; Rutka, James T.; Dirks, Peter; Pfister, Stefan M.; Merchant, Thomas E.; Gilbert, Mark R.; Armstrong, Terri S.; Korshunov, Andrey; Ellison, David W.

    2016-01-01

    Purpose Posterior fossa ependymoma comprises two distinct molecular variants termed EPN_PFA and EPN_PFB that have a distinct biology and natural history. The therapeutic value of cytoreductive surgery and radiation therapy for posterior fossa ependymoma after accounting for molecular subgroup is not known. Methods Four independent nonoverlapping retrospective cohorts of posterior fossa ependymomas (n = 820) were profiled using genome-wide methylation arrays. Risk stratification models were designed based on known clinical and newly described molecular biomarkers identified by multivariable Cox proportional hazards analyses. Results Molecular subgroup is a powerful independent predictor of outcome even when accounting for age or treatment regimen. Incompletely resected EPN_PFA ependymomas have a dismal prognosis, with a 5-year progression-free survival ranging from 26.1% to 56.8% across all four cohorts. Although first-line (adjuvant) radiation is clearly beneficial for completely resected EPN_PFA, a substantial proportion of patients with EPN_PFB can be cured with surgery alone, and patients with relapsed EPN_PFB can often be treated successfully with delayed external-beam irradiation. Conclusion The most impactful biomarker for posterior fossa ependymoma is molecular subgroup affiliation, independent of other demographic or treatment variables. However, both EPN_PFA and EPN_PFB still benefit from increased extent of resection, with the survival rates being particularly poor for subtotally resected EPN_PFA, even with adjuvant radiation therapy. Patients with EPN_PFB who undergo gross total resection are at lower risk for relapse and should be considered for inclusion in a randomized clinical trial of observation alone with radiation reserved for those who experience recurrence. PMID:27269943

  16. Using Horn's Parallel Analysis Method in Exploratory Factor Analysis for Determining the Number of Factors

    ERIC Educational Resources Information Center

    Çokluk, Ömay; Koçak, Duygu

    2016-01-01

    In this study, the number of factors obtained from parallel analysis, a method used for determining the number of factors in exploratory factor analysis, was compared to that of the factors obtained from eigenvalue and scree plot--two traditional methods for determining the number of factors--in terms of consistency. Parallel analysis is based on…

  17. Determining the Number of Factors in P-Technique Factor Analysis

    ERIC Educational Resources Information Center

    Lo, Lawrence L.; Molenaar, Peter C. M.; Rovine, Michael

    2017-01-01

    Determining the number of factors is a critical first step in exploratory factor analysis. Although various criteria and methods for determining the number of factors have been evaluated in the usual between-subjects R-technique factor analysis, there is still question of how these methods perform in within-subjects P-technique factor analysis. A…

  18. Therapeutic Impact of Cytoreductive Surgery and Irradiation of Posterior Fossa Ependymoma in the Molecular Era: A Retrospective Multicohort Analysis.

    PubMed

    Ramaswamy, Vijay; Hielscher, Thomas; Mack, Stephen C; Lassaletta, Alvaro; Lin, Tong; Pajtler, Kristian W; Jones, David T W; Luu, Betty; Cavalli, Florence M G; Aldape, Kenneth; Remke, Marc; Mynarek, Martin; Rutkowski, Stefan; Gururangan, Sridharan; McLendon, Roger E; Lipp, Eric S; Dunham, Christopher; Hukin, Juliette; Eisenstat, David D; Fulton, Dorcas; van Landeghem, Frank K H; Santi, Mariarita; van Veelen, Marie-Lise C; Van Meir, Erwin G; Osuka, Satoru; Fan, Xing; Muraszko, Karin M; Tirapelli, Daniela P C; Oba-Shinjo, Sueli M; Marie, Suely K N; Carlotti, Carlos G; Lee, Ji Yeoun; Rao, Amulya A Nageswara; Giannini, Caterina; Faria, Claudia C; Nunes, Sofia; Mora, Jaume; Hamilton, Ronald L; Hauser, Peter; Jabado, Nada; Petrecca, Kevin; Jung, Shin; Massimi, Luca; Zollo, Massimo; Cinalli, Giuseppe; Bognár, László; Klekner, Almos; Hortobágyi, Tibor; Leary, Sarah; Ermoian, Ralph P; Olson, James M; Leonard, Jeffrey R; Gardner, Corrine; Grajkowska, Wieslawa A; Chambless, Lola B; Cain, Jason; Eberhart, Charles G; Ahsan, Sama; Massimino, Maura; Giangaspero, Felice; Buttarelli, Francesca R; Packer, Roger J; Emery, Lyndsey; Yong, William H; Soto, Horacio; Liau, Linda M; Everson, Richard; Grossbach, Andrew; Shalaby, Tarek; Grotzer, Michael; Karajannis, Matthias A; Zagzag, David; Wheeler, Helen; von Hoff, Katja; Alonso, Marta M; Tuñon, Teresa; Schüller, Ulrich; Zitterbart, Karel; Sterba, Jaroslav; Chan, Jennifer A; Guzman, Miguel; Elbabaa, Samer K; Colman, Howard; Dhall, Girish; Fisher, Paul G; Fouladi, Maryam; Gajjar, Amar; Goldman, Stewart; Hwang, Eugene; Kool, Marcel; Ladha, Harshad; Vera-Bolanos, Elizabeth; Wani, Khalida; Lieberman, Frank; Mikkelsen, Tom; Omuro, Antonio M; Pollack, Ian F; Prados, Michael; Robins, H Ian; Soffietti, Riccardo; Wu, Jing; Metellus, Phillipe; Tabori, Uri; Bartels, Ute; Bouffet, Eric; Hawkins, Cynthia E; Rutka, James T; Dirks, Peter; Pfister, Stefan M; Merchant, Thomas E; Gilbert, Mark R; Armstrong, Terri S; Korshunov, Andrey; Ellison, David W; Taylor, Michael D

    2016-07-20

    Posterior fossa ependymoma comprises two distinct molecular variants termed EPN_PFA and EPN_PFB that have a distinct biology and natural history. The therapeutic value of cytoreductive surgery and radiation therapy for posterior fossa ependymoma after accounting for molecular subgroup is not known. Four independent nonoverlapping retrospective cohorts of posterior fossa ependymomas (n = 820) were profiled using genome-wide methylation arrays. Risk stratification models were designed based on known clinical and newly described molecular biomarkers identified by multivariable Cox proportional hazards analyses. Molecular subgroup is a powerful independent predictor of outcome even when accounting for age or treatment regimen. Incompletely resected EPN_PFA ependymomas have a dismal prognosis, with a 5-year progression-free survival ranging from 26.1% to 56.8% across all four cohorts. Although first-line (adjuvant) radiation is clearly beneficial for completely resected EPN_PFA, a substantial proportion of patients with EPN_PFB can be cured with surgery alone, and patients with relapsed EPN_PFB can often be treated successfully with delayed external-beam irradiation. The most impactful biomarker for posterior fossa ependymoma is molecular subgroup affiliation, independent of other demographic or treatment variables. However, both EPN_PFA and EPN_PFB still benefit from increased extent of resection, with the survival rates being particularly poor for subtotally resected EPN_PFA, even with adjuvant radiation therapy. Patients with EPN_PFB who undergo gross total resection are at lower risk for relapse and should be considered for inclusion in a randomized clinical trial of observation alone with radiation reserved for those who experience recurrence. © 2016 by American Society of Clinical Oncology.

  19. Frequency analysis of uncertain structures using imprecise probability

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

    Modares, Mehdi; Bergerson, Joshua

    2015-01-01

    Two new methods for finite element based frequency analysis of a structure with uncertainty are developed. An imprecise probability formulation based on enveloping p-boxes is used to quantify the uncertainty present in the mechanical characteristics of the structure. For each element, independent variations are considered. Using the two developed methods, P-box Frequency Analysis (PFA) and Interval Monte-Carlo Frequency Analysis (IMFA), sharp bounds on natural circular frequencies at different probability levels are obtained. These methods establish a framework for handling incomplete information in structural dynamics. Numerical example problems are presented that illustrate the capabilities of the new methods along with discussionsmore » on their computational efficiency.« less

  20. Phosphorylation of CMG helicase and Tof1 is required for programmed fork arrest

    PubMed Central

    Bastia, Deepak; Srivastava, Pankaj; Zaman, Shamsu; Choudhury, Malay; Mohanty, Bidyut K.; Bacal, Julien; Langston, Lance D.; Pasero, Philippe; O’Donnell, Michael E.

    2016-01-01

    Several important physiological transactions, including control of replicative life span (RLS), prevention of collision between replication and transcription, and cellular differentiation, require programmed replication fork arrest (PFA). However, a general mechanism of PFA has remained elusive. We previously showed that the Tof1–Csm3 fork protection complex is essential for PFA by antagonizing the Rrm3 helicase that displaces nonhistone protein barriers that impede fork progression. Here we show that mutations of Dbf4-dependent kinase (DDK) of Saccharomyces cerevisiae, but not other DNA replication factors, greatly reduced PFA at replication fork barriers in the spacer regions of the ribosomal DNA array. A key target of DDK is the mini chromosome maintenance (Mcm) 2–7 complex, which is known to require phosphorylation by DDK to form an active CMG [Cdc45 (cell division cycle gene 45), Mcm2–7, GINS (Go, Ichi, Ni, and San)] helicase. In vivo experiments showed that mutational inactivation of DDK caused release of Tof1 from the chromatin fractions. In vitro binding experiments confirmed that CMG and/or Mcm2–7 had to be phosphorylated for binding to phospho-Tof1–Csm3 but not to its dephosphorylated form. Suppressor mutations that bypass the requirement for Mcm2–7 phosphorylation by DDK restored PFA in the absence of the kinase. Retention of Tof1 in the chromatin fraction and PFA in vivo was promoted by the suppressor mcm5-bob1, which bypassed DDK requirement, indicating that under this condition a kinase other than DDK catalyzed the phosphorylation of Tof1. We propose that phosphorylation regulates the recruitment and retention of Tof1–Csm3 by the replisome and that this complex antagonizes the Rrm3 helicase, thereby promoting PFA, by preserving the integrity of the Fob1–Ter complex. PMID:27298353

  1. Chemical analysis of raw and processed Fructus arctii by high-performance liquid chromatography/diode array detection-electrospray ionization-mass spectrometry

    PubMed Central

    Qin, Kunming; Liu, Qidi; Cai, Hao; Cao, Gang; Lu, Tulin; Shen, Baojia; Shu, Yachun; Cai, Baochang

    2014-01-01

    Background: In traditional Chinese medicine (TCM), raw and processed herbs are used to treat the different diseases. Fructus Arctii, the dried fruits of Arctium lappa l. (Compositae), is widely used in the TCM. Stir-frying is the most common processing method, which might modify the chemical compositions in Fructus Arctii. Materials and Methods: To test this hypothesis, we focused on analysis and identification of the main chemical constituents in raw and processed Fructus Arctii (PFA) by high-performance liquid chromatography/diode array detection-electrospray ionization-mass spectrometry. Results: The results indicated that there was less arctiin in stir-fried materials than in raw materials. however, there were higher levels of arctigenin in stir-fried materials than in raw materials. Conclusion: We suggest that arctiin reduced significantly following the thermal conversion of arctiin to arctigenin. In conclusion, this finding may shed some light on understanding the differences in the therapeutic values of raw versus PFA in TCM. PMID:25422559

  2. Tularosa Basin Play Fairway Analysis

    DOE Data Explorer

    Adam Brandt

    2015-11-15

    This submission contains several shapefiles used for a deterministic PFA, as well as a heat composite risk segment with union overlay, and training sites used for weights of evidence. More detailed metadata can be found in the specific file.

  3. A preliminary evaluation of the training effects of a didactic and simulation-based psychological first aid program in students and school counselors in South Korea.

    PubMed

    Lee, Jong-Sun; You, Sungeun; Choi, Yun-Kyeung; Youn, Hyae-Young; Shin, Hye Sook

    2017-01-01

    The present study aimed to examine the training effects of a didactic and simulation-based psychological first aid (PFA) program. Based on the competency-based model, the study sought to examine whether the PFA training would enhance knowledge, skills, and attitudes. Study 1 examined the training effects of the PFA program in a sample of undergraduate and graduate students in psychology. Study 2 was conducted with school counselors. In both studies, all participants completed a one-day PFA workshop with a 3-hour didactic lecture and a 3-hour simulation-based practice. Assessments were conducted prior to the didactic lecture and upon completion of the simulation-based practice. In study 1, an examination of pre- and posttest comparisons indicated that the training significantly improved students' PFA knowledge and perceived competence in PFA skill. In study 2, the same PFA training significantly improved school counselors' PFA knowledge, perceived competence in PFA skill, perceived preparedness and confidence to provide psychological assistance for future disasters, but their perceived willingness to participate in psychological assistance did not significantly change after the training. This study provides preliminary evidence supporting the effectiveness of the PFA training program using a combined method of didactic and simulation-based practice for disaster mental health providers in Korea.

  4. A preliminary evaluation of the training effects of a didactic and simulation-based psychological first aid program in students and school counselors in South Korea

    PubMed Central

    Lee, Jong-Sun; Choi, Yun-Kyeung; Youn, Hyae-young; Shin, Hye Sook

    2017-01-01

    The present study aimed to examine the training effects of a didactic and simulation-based psychological first aid (PFA) program. Based on the competency-based model, the study sought to examine whether the PFA training would enhance knowledge, skills, and attitudes. Study 1 examined the training effects of the PFA program in a sample of undergraduate and graduate students in psychology. Study 2 was conducted with school counselors. In both studies, all participants completed a one-day PFA workshop with a 3-hour didactic lecture and a 3-hour simulation-based practice. Assessments were conducted prior to the didactic lecture and upon completion of the simulation-based practice. In study 1, an examination of pre- and posttest comparisons indicated that the training significantly improved students’ PFA knowledge and perceived competence in PFA skill. In study 2, the same PFA training significantly improved school counselors’ PFA knowledge, perceived competence in PFA skill, perceived preparedness and confidence to provide psychological assistance for future disasters, but their perceived willingness to participate in psychological assistance did not significantly change after the training. This study provides preliminary evidence supporting the effectiveness of the PFA training program using a combined method of didactic and simulation-based practice for disaster mental health providers in Korea. PMID:28715481

  5. DHA Production in Escherichia coli by Expressing Reconstituted Key Genes of Polyketide Synthase Pathway from Marine Bacteria.

    PubMed

    Peng, Yun-Feng; Chen, Wen-Chao; Xiao, Kang; Xu, Lin; Wang, Lian; Wan, Xia

    2016-01-01

    The gene encoding phosphopantetheinyl transferase (PPTase), pfaE, a component of the polyketide synthase (PKS) pathway, is crucial for the production of docosahexaenoic acid (DHA, 22:6ω3), along with the other pfa cluster members pfaA, pfaB, pfaC and pfaD. DHA was produced in Escherichia coli by co-expressing pfaABCD from DHA-producing Colwellia psychrerythraea 34H with one of four pfaE genes from bacteria producing arachidonic acid (ARA, 20:4ω6), eicosapentaenoic acid (EPA, 20:5ω3) or DHA, respectively. Substitution of the pfaE gene from different strain source in E. coli did not influence the function of the PKS pathway producing DHA, although they led to different DHA yields and fatty acid profiles. This result suggested that the pfaE gene could be switchable between these strains for the production of DHA. The DHA production by expressing the reconstituted PKS pathway was also investigated in different E. coli strains, at different temperatures, or with the treatment of cerulenin. The highest DHA production, 2.2 mg of DHA per gram of dry cell weight or 4.1% of total fatty acids, was obtained by co-expressing pfaE(EPA) from the EPA-producing strain Shewanella baltica with pfaABCD in DH5α. Incubation at low temperature (10-15°C) resulted in higher accumulation of DHA compared to higher temperatures. The addition of cerulenin to the medium increased the proportion of DHA and saturated fatty acids, including C12:0, C14:0 and C16:0, at the expense of monounsaturated fatty acids, including C16:1 and C18:1. Supplementation with 1 mg/L cerulenin resulted in the highest DHA yield of 2.4 mg/L upon co-expression of pfaE(DHA) from C. psychrerythraea.

  6. Potential Flow Model for Compressible Stratified Rayleigh-Taylor Instability

    NASA Astrophysics Data System (ADS)

    Rydquist, Grant; Reckinger, Scott; Owkes, Mark; Wieland, Scott

    2017-11-01

    The Rayleigh-Taylor Instability (RTI) is an instability that occurs when a heavy fluid lies on top of a lighter fluid in a gravitational field, or a gravity-like acceleration. It occurs in many fluid flows of a highly compressive nature. In this study potential flow analysis (PFA) is used to model the early stages of RTI growth for compressible fluids. In the localized region near the bubble tip, the effects of vorticity are negligible, so PFA is applicable, as opposed to later stages where the induced velocity due to vortices generated from the growth of the instability dominate the flow. The incompressible PFA is extended for compressibility effects by applying the growth rate and the associated perturbation spatial decay from compressible linear stability theory. The PFA model predicts theoretical values for a bubble terminal velocity for single-mode compressible RTI, dependent upon the Atwood (A) and Mach (M) numbers, which is a parameter that measures both the strength of the stratification and intrinsic compressibility. The theoretical bubble terminal velocities are compared against numerical simulations. The PFA model correctly predicts the M dependence at high A, but the model must be further extended to include additional physics to capture the behavior at low A. Undergraduate Scholars Program - Montana State University.

  7. GPFA-AB_Phase1RiskAnalysisTask5DataUpload

    DOE Data Explorer

    Teresa E. Jordan

    2015-09-30

    This submission contains information used to compute the risk factors for the GPFA-AB project (DE-EE0006726). The risk factors are natural reservoir quality, thermal resource quality, potential for induced seismicity, and utilization. The methods used to combine the risk factors included taking the product, sum, and minimum of the four risk factors. The files are divided into images, rasters, shapefiles, and supporting information. The image files show what the raster and shapefiles should look like. The raster files contain the input risk factors, calculation of the scaled risk factors, and calculation of the combined risk factors. The shapefiles include definition of the fairways, definition of the US Census Places, the center of the raster cells, and locations of industries. Supporting information contains details of the calculations or processing used in generating the files. An image of the raster will have the same name except *.png as the file ending instead of *.tif. Images with “fairways” or “industries” added to the name are composed of a raster with the relevant shapefile added. The file About_GPFA-AB_Phase1RiskAnalysisTask5DataUpload.pdf contains information the citation, special use considerations, authorship, etc. More details on each file are given in the spreadsheet “list_of_contents.csv” in the folder “SupportingInfo”. Code used to calculate values is available at https://github.com/calvinwhealton/geothermal_pfa under the folder “combining_metrics”.

  8. Patellofemoral arthroplasty in a bilateral Syme's amputee.

    PubMed

    Kanna, Raj; Barrett, David S

    2016-01-01

    We present the case of a 50-year-old woman, who is a bilateral Syme's amputee and subsequently underwent patellofemoral arthroplasty (PFA) for osteoarthritis primarily involving the patellofemoral (PF) joint. History and physical examination were suggestive of severe PF arthritis without patellar instability of the right knee. The diagnosis was confirmed by roentgenogram and a PFA was performed. A slightly modified rehabilitation program was implemented and the patient was followed until 6 years after surgery. In comparison to the preoperative scores, the Oxford, the Western Ontario and McMaster Universities (WOMAC), the Knee Society, and the Hospital for Special Surgery Knee Scores improved significantly (p < 0.05) at the time of final follow-up. PF problems specific to below-knee amputees, factors to be considered before performing PFA, and the drawbacks of other treatment modalities in these patients have been discussed.

  9. Factors affecting construction performance: exploratory factor analysis

    NASA Astrophysics Data System (ADS)

    Soewin, E.; Chinda, T.

    2018-04-01

    The present work attempts to develop a multidimensional performance evaluation framework for a construction company by considering all relevant measures of performance. Based on the previous studies, this study hypothesizes nine key factors, with a total of 57 associated items. The hypothesized factors, with their associated items, are then used to develop questionnaire survey to gather data. The exploratory factor analysis (EFA) was applied to the collected data which gave rise 10 factors with 57 items affecting construction performance. The findings further reveal that the items constituting ten key performance factors (KPIs) namely; 1) Time, 2) Cost, 3) Quality, 4) Safety & Health, 5) Internal Stakeholder, 6) External Stakeholder, 7) Client Satisfaction, 8) Financial Performance, 9) Environment, and 10) Information, Technology & Innovation. The analysis helps to develop multi-dimensional performance evaluation framework for an effective measurement of the construction performance. The 10 key performance factors can be broadly categorized into economic aspect, social aspect, environmental aspect, and technology aspects. It is important to understand a multi-dimension performance evaluation framework by including all key factors affecting the construction performance of a company, so that the management level can effectively plan to implement an effective performance development plan to match with the mission and vision of the company.

  10. Extension Procedures for Confirmatory Factor Analysis

    ERIC Educational Resources Information Center

    Nagy, Gabriel; Brunner, Martin; Lüdtke, Oliver; Greiff, Samuel

    2017-01-01

    We present factor extension procedures for confirmatory factor analysis that provide estimates of the relations of common and unique factors with external variables that do not undergo factor analysis. We present identification strategies that build upon restrictions of the pattern of correlations between unique factors and external variables. The…

  11. Influence of Finite Element Size in Residual Strength Prediction of Composite Structures

    NASA Technical Reports Server (NTRS)

    Satyanarayana, Arunkumar; Bogert, Philip B.; Karayev, Kazbek Z.; Nordman, Paul S.; Razi, Hamid

    2012-01-01

    The sensitivity of failure load to the element size used in a progressive failure analysis (PFA) of carbon composite center notched laminates is evaluated. The sensitivity study employs a PFA methodology previously developed by the authors consisting of Hashin-Rotem intra-laminar fiber and matrix failure criteria and a complete stress degradation scheme for damage simulation. The approach is implemented with a user defined subroutine in the ABAQUS/Explicit finite element package. The effect of element size near the notch tips on residual strength predictions was assessed for a brittle failure mode with a parametric study that included three laminates of varying material system, thickness and stacking sequence. The study resulted in the selection of an element size of 0.09 in. X 0.09 in., which was later used for predicting crack paths and failure loads in sandwich panels and monolithic laminated panels. Comparison of predicted crack paths and failure loads for these panels agreed well with experimental observations. Additionally, the element size vs. normalized failure load relationship, determined in the parametric study, was used to evaluate strength-scaling factors for three different element sizes. The failure loads predicted with all three element sizes provided converged failure loads with respect to that corresponding with the 0.09 in. X 0.09 in. element size. Though preliminary in nature, the strength-scaling concept has the potential to greatly reduce the computational time required for PFA and can enable the analysis of large scale structural components where failure is dominated by fiber failure in tension.

  12. Beyond-proximity-force-approximation Casimir force between two spheres at finite temperature

    NASA Astrophysics Data System (ADS)

    Bimonte, Giuseppe

    2018-04-01

    A recent experiment [J. L. Garrett, D. A. T. Somers, and J. N. Munday, Phys. Rev. Lett. 120, 040401 (2018), 10.1103/PhysRevLett.120.040401] measured for the first time the gradient of the Casimir force between two gold spheres at room temperature. The theoretical analysis of the data was carried out using the standard proximity force approximation (PFA). A fit of the data, using a parametrization of the force valid for the sphere-plate geometry, was used by the authors to place a bound on deviations from PFA. Motivated by this work, we compute the Casimir force between two gold spheres at finite temperature. The semianalytic formula for the Casimir force that we construct is valid for all separations, and can be easily used to interpret future experiments in both the sphere-plate and sphere-sphere configurations. We describe the correct parametrization of the corrections to PFA for two spheres that should be used in data analysis.

  13. Implementing psychological first-aid training for medical reserve corps volunteers.

    PubMed

    Chandra, Anita; Kim, Jee; Pieters, Huibrie C; Tang, Jennifer; McCreary, Michael; Schreiber, Merritt; Wells, Kenneth

    2014-02-01

    We assessed the feasibility and impact on knowledge, attitudes, and reported practices of psychological first-aid (PFA) training in a sample of Medical Reserve Corps (MRC) members. Data have been limited on the uptake of PFA training in surge responders (eg, MRC) who are critical to community response. Our mixed-methods approach involved self-administered pre- and post-training surveys and within-training focus group discussions of 76 MRC members attending a PFA training and train-the-trainer workshop. Listen, protect, connect (a PFA model for lay persons) focuses on listening and understanding both verbal and nonverbal cues; protecting the individual by determining realistic ways to help while providing reassurance; and connecting the individual with resources in the community. From pre- to post-training, perceived confidence and capability in using PFA after an emergency or disaster increased from 71% to 90% (P < .01), but no significant increase was found in PFA-related knowledge. Qualitative analyses suggest that knowledge and intentions to use PFA increased with training. Brief training was feasible, and while results were modest, the PFA training resulted in greater reported confidence and perceived capability in addressing psychological distress of persons affected by public health threats. PFA training is a promising approach to improve surge responder confidence and competency in addressing postdisaster needs.

  14. Compression After Impact on Honeycomb Core Sandwich Panels with Thin Facesheets, Part 2: Analysis

    NASA Technical Reports Server (NTRS)

    Mcquigg, Thomas D.; Kapania, Rakesh K.; Scotti, Stephen J.; Walker, Sandra P.

    2012-01-01

    A two part research study has been completed on the topic of compression after impact (CAI) of thin facesheet honeycomb core sandwich panels. The research has focused on both experiments and analysis in an effort to establish and validate a new understanding of the damage tolerance of these materials. Part 2, the subject of the current paper, is focused on the analysis, which corresponds to the CAI testings described in Part 1. Of interest, are sandwich panels, with aerospace applications, which consist of very thin, woven S2-fiberglass (with MTM45-1 epoxy) facesheets adhered to a Nomex honeycomb core. Two sets of materials, which were identical with the exception of the density of the honeycomb core, were tested in Part 1. The results highlighted the need for analysis methods which taken into account multiple failure modes. A finite element model (FEM) is developed here, in Part 2. A commercial implementation of the Multicontinuum Failure Theory (MCT) for progressive failure analysis (PFA) in composite laminates, Helius:MCT, is included in this model. The inclusion of PFA in the present model provided a new, unique ability to account for multiple failure modes. In addition, significant impact damage detail is included in the model. A sensitivity study, used to assess the effect of each damage parameter on overall analysis results, is included in an appendix. Analysis results are compared to the experimental results for each of the 32 CAI sandwich panel specimens tested to failure. The failure of each specimen is predicted using the high-fidelity, physicsbased analysis model developed here, and the results highlight key improvements in the understanding of honeycomb core sandwich panel CAI failure. Finally, a parametric study highlights the strength benefits compared to mass penalty for various core densities.

  15. Patellofemoral arthroplasty in a bilateral Syme's amputee

    PubMed Central

    Kanna, Raj; Barrett, David S.

    2016-01-01

    We present the case of a 50-year-old woman, who is a bilateral Syme's amputee and subsequently underwent patellofemoral arthroplasty (PFA) for osteoarthritis primarily involving the patellofemoral (PF) joint. History and physical examination were suggestive of severe PF arthritis without patellar instability of the right knee. The diagnosis was confirmed by roentgenogram and a PFA was performed. A slightly modified rehabilitation program was implemented and the patient was followed until 6 years after surgery. In comparison to the preoperative scores, the Oxford, the Western Ontario and McMaster Universities (WOMAC), the Knee Society, and the Hospital for Special Surgery Knee Scores improved significantly (p < 0.05) at the time of final follow-up. PF problems specific to below-knee amputees, factors to be considered before performing PFA, and the drawbacks of other treatment modalities in these patients have been discussed. PMID:26908975

  16. Exploratory Bi-factor Analysis: The Oblique Case.

    PubMed

    Jennrich, Robert I; Bentler, Peter M

    2012-07-01

    Bi-factor analysis is a form of confirmatory factor analysis originally introduced by Holzinger and Swineford (Psychometrika 47:41-54, 1937). The bi-factor model has a general factor, a number of group factors, and an explicit bi-factor structure. Jennrich and Bentler (Psychometrika 76:537-549, 2011) introduced an exploratory form of bi-factor analysis that does not require one to provide an explicit bi-factor structure a priori. They use exploratory factor analysis and a bifactor rotation criterion designed to produce a rotated loading matrix that has an approximate bi-factor structure. Among other things this can be used as an aid in finding an explicit bi-factor structure for use in a confirmatory bi-factor analysis. They considered only orthogonal rotation. The purpose of this paper is to consider oblique rotation and to compare it to orthogonal rotation. Because there are many more oblique rotations of an initial loading matrix than orthogonal rotations, one expects the oblique results to approximate a bi-factor structure better than orthogonal rotations and this is indeed the case. A surprising result arises when oblique bi-factor rotation methods are applied to ideal data.

  17. Folate supplementation to prevent birth abnormalities: evaluating a community-based participatory action plan for refugees and migrant workers on the Thailand-Myanmar border.

    PubMed

    Stevens, A; Gilder, M E; Moo, P; Hashmi, A; Toe, S E T; Doh, B B; Nosten, S; Chotivanich, K; Somerset, Shawn; McGready, Rose

    2018-06-20

    Preconception folic acid (PFA) taken at least 3 months before conception can decrease the incidence of neural tube defects (NTDs) by approximately 46%. NTDs contribute significantly to neonatal morbidity and mortality in migrant and refugee populations on the Thailand-Myanmar border (incidence 1.57/1000 live births). This audit aimed to assess uptake of PFA among migrant and refugee women, evaluate knowledge about PFA among local healthcare workers and implement a participatory community intervention to increase PFA uptake and decrease NTD incidence in this population. A mixed-methods baseline evaluation was followed by an intervention involving health worker education and a community outreach program. A follow-up audit was performed 18 months post-intervention. Data were gathered via surveys, short interviews and focus group discussions. The intervention program included community-based workshops, production and distribution of printed flyers and posters, and outreach to various local organisations. Uptake of PFA was <2% both before and after the intervention. Despite a substantial increase in local healthcare worker knowledge of PFA, no significant improvement in PFA uptake after the intervention was detected. Most pregnancies in this local community sample were reported to be unplanned. High rates of NTDs with low PFA uptake remains a major public health challenge in this transient population. Results indicate that improved health worker knowledge alone is not sufficient to enhance PFA uptake in this population. Integration of PFA education within expanded family planning programs and broad-based food fortification may be more effective. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  18. Psychological First Aid

    PubMed Central

    Shultz, James M; Forbes, David

    2014-01-01

    Psychological first aid (PFA) has become the flagship early intervention for disaster survivors, with recent adaptations for disaster responders, in the post-9/11 era. PFA is broadly endorsed by expert consensus and integrated into guidelines for mental health and psychosocial support in disasters and extreme events. PFA frameworks are proliferating, with increasing numbers of models developed for delivery by a range of providers for use with an expanding array of target populations. Despite popularity and promotion there remains a dearth of evidence for effectiveness and recent independent reviews of PFA have highlighted this important gap. This commentary juxtaposes the current propagation of PFA against the compelling need to produce evidence for effectiveness and suggests a series of actions to prioritize and expedite real-time, real-event field evaluation of PFA. PMID:28228996

  19. Psychological First Aid: Rapid proliferation and the search for evidence.

    PubMed

    Shultz, James M; Forbes, David

    2014-01-01

    Psychological first aid (PFA) has become the flagship early intervention for disaster survivors, with recent adaptations for disaster responders, in the post-9/11 era. PFA is broadly endorsed by expert consensus and integrated into guidelines for mental health and psychosocial support in disasters and extreme events. PFA frameworks are proliferating, with increasing numbers of models developed for delivery by a range of providers for use with an expanding array of target populations. Despite popularity and promotion there remains a dearth of evidence for effectiveness and recent independent reviews of PFA have highlighted this important gap. This commentary juxtaposes the current propagation of PFA against the compelling need to produce evidence for effectiveness and suggests a series of actions to prioritize and expedite real-time, real-event field evaluation of PFA.

  20. Effect of pulverized fuel ash and CO{sub 2} curing on the water resistance of magnesium oxychloride cement (MOC)

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

    He, Pingping; Poon, Chi Sun, E-mail: cecspoon@polyu.edu.hk; Tsang, Daniel C.W.

    This paper presents a study on the use of pulverized fuel ash (PFA) to improve the water resistance of magnesium oxychloride cement (MOC). Strength retention coefficients and volume stability were tested to evaluate the water resistance of MOC, in which the addition of PFA resulted in a remarkable improvement. The characterization of hydration products before and after water immersion was carried out using quantitative X-ray diffraction (QXRD), thermogravimetric (TG), Fourier-transformed infrared spectroscopy (FTIR) and scanning electron microscope (SEM). With the Q-XRD analysis, it was shown that the addition of PFA could result in the great increase of the amount ofmore » amorphous phase during air curing. This amorphous gel was identified as a mixture of magnesium-chloride-silicate-hydrate gel (M-Cl-S-H gel) and magnesium-chloride-hydrate gel (M-Cl-H gel) by elemental mapping scanning. It suggested that PFA could not only react with MOC to form M-Cl-S-H gel, but also change the morphology of magnesium oxychloride. The generation of insoluble M-Cl-S-H gel and M-Cl-H gel and densification of the microstructure contributed to the improvement of the water resistance of MOC. The MOC mortar expanded during air curing due to the hydration of excess MgO. Water immersion led to more expansion of MOC mortar as a result of the continuously hydration of excess MgO and the formation of Mg(OH){sub 2}. Adding PFA could increase the expansion of MOC mortar during air curing, which may because the amorphous gel could remain more water and benefit to the hydration of MgO. While, the addition of PFA could decrease the expansion of cement mortar during water immersion perhaps due to the reduction of the content of excess MgO and the insoluble amorphous-gel-layer that protect the MgO from hydration. Moreover, CO{sub 2} curing could further improve the performance of the PFA-blended MOC due to the formation of a higher content of amorphous gel.« less

  1. Exploratory Bi-Factor Analysis: The Oblique Case

    ERIC Educational Resources Information Center

    Jennrich, Robert I.; Bentler, Peter M.

    2012-01-01

    Bi-factor analysis is a form of confirmatory factor analysis originally introduced by Holzinger and Swineford ("Psychometrika" 47:41-54, 1937). The bi-factor model has a general factor, a number of group factors, and an explicit bi-factor structure. Jennrich and Bentler ("Psychometrika" 76:537-549, 2011) introduced an exploratory form of bi-factor…

  2. Bayesian Exploratory Factor Analysis

    PubMed Central

    Conti, Gabriella; Frühwirth-Schnatter, Sylvia; Heckman, James J.; Piatek, Rémi

    2014-01-01

    This paper develops and applies a Bayesian approach to Exploratory Factor Analysis that improves on ad hoc classical approaches. Our framework relies on dedicated factor models and simultaneously determines the number of factors, the allocation of each measurement to a unique factor, and the corresponding factor loadings. Classical identification criteria are applied and integrated into our Bayesian procedure to generate models that are stable and clearly interpretable. A Monte Carlo study confirms the validity of the approach. The method is used to produce interpretable low dimensional aggregates from a high dimensional set of psychological measurements. PMID:25431517

  3. A graduated food addiction classifications approach significantly differentiates depression, anxiety and stress among people with type 2 diabetes.

    PubMed

    Raymond, Karren-Lee; Kannis-Dymand, Lee; Lovell, Geoff P

    2017-10-01

    To examine differences in depression, anxiety, and stress across people with type 2 diabetes mellitus (t2d) classified according to a four level processed food addiction (PFA) severity indicator dichotomy. Four hundred and eight participants with a t2d diagnoses completed an online survey including the Yale Food Addiction Scale (YFAS) and the DASS-21. Based on YFAS symptom counts participants were classified as either: non-PFA; mild-PFA; moderate-PFA; or severe-PFA. Multivariate, λ=0.422, F(9,978.51)=46.286, p<0.001, n p 2 =0.250, and univariate analyses of variance demonstrated that depression F(3,408)=159.891, p<0.001, n p 2 =0.543, anxiety F(3,408)=127.419, p<0.001, n p 2 =0.486, and stress scores F(3,408)=129.714, p<0.001, n p 2 =0.491, significantly and meaningfully increased from one PFA classification level to the next. Furthermore, the proportion of participants with more severe classifications of depression χ 2 (12)=297.820, p<0.001, anxiety χ 2 (12)=271.805, p<0.001, and stress χ 2 (12)=240.875, p<0.001, were significantly higher in the more severe PFA groupings. For people with t2d, PFA is an important and meaningful associate of depression, anxiety, and stress, and that the adopted four level PFA severity indicator dichotomy is valid and useful. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Quality characteristics of pork burger added with albedo-fiber powder obtained from yellow passion fruit (Passiflora edulis var. flavicarpa) co-products.

    PubMed

    López-Vargas, Jairo H; Fernández-López, Juana; Pérez-Álvarez, José Ángel; Viuda-Martos, Manuel

    2014-06-01

    The aim of this work determined the technological, nutritional and sensory characteristics of pork burgers, added with different concentrations (2.5 and 5%) of passion fruit albedo (PFA) co-product, obtained from passion fruit juice processing. The addition of PFA on pork burgers improves their nutritional value (higher fiber content). In raw and cooked burger, all textural parameters, except springiness and cohesiveness, were affected by the incorporation of PFA. PFA addition was found to be effective improving the cooking yield, moisture retention and fat retention. The raw and cooked pork burgers added with PFA had lower TBA values and lower counts of aerobic mesophilic bacteria and enterobacteria than the control samples. No Escherichia coli and molds were found in the samples. The overall acceptability scores showed that the most appreciated sample was the one containing 2.5% PFA. According to the results obtained, 2.5 and 5% of PFA addition can be recommended in pork burger production as a new dietary fiber source. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Plasma versus Drude Modeling of the Casimir Force: Beyond the Proximity Force Approximation

    NASA Astrophysics Data System (ADS)

    Hartmann, Michael; Ingold, Gert-Ludwig; Neto, Paulo A. Maia

    2017-07-01

    We calculate the Casimir force and its gradient between a spherical and a planar gold surface. Significant numerical improvements allow us to extend the range of accessible parameters into the experimental regime. We compare our numerically exact results with those obtained within the proximity force approximation (PFA) employed in the analysis of all Casimir force experiments reported in the literature so far. Special attention is paid to the difference between the Drude model and the dissipationless plasma model at zero frequency. It is found that the correction to PFA is too small to explain the discrepancy between the experimental data and the PFA result based on the Drude model. However, it turns out that for the plasma model, the corrections to PFA lie well outside the experimental bound obtained by probing the variation of the force gradient with the sphere radius [D. E. Krause et al., Phys. Rev. Lett. 98, 050403 (2007), 10.1103/PhysRevLett.98.050403]. The corresponding corrections based on the Drude model are significantly smaller but still in violation of the experimental bound for small distances between plane and sphere.

  6. Hydroxyapatite-phosphonoformic acid hybrid compounds prepared by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Turki, Thouraya; Othmani, Masseoud; Bantignies, Jean-Louis; Bouzouita, Khaled

    2014-01-01

    Hydroxyapatites were prepared in the presence of different amounts of phosphonoformic acid (PFA) via the hydrothermal method. The obtained powders were characterized through chemical analysis, XRD, IR, 31P MAS-NMR, TEM, and TG-TDA. The XRD showed that the PFA did not affect the apatite composition. Indeed, only a reduction of the crystallite size was noted. After grafting of PFA, the IR spectroscopy revealed the appearance of new bands belonging to HPO42- and carboxylate groups of the apatite and organic moiety, respectively. Moreover, the 31P MAS-NMR spectra exhibited a peak with a low intensity assigned to the terminal phosphonate group of the organic moiety in addition to that of the apatite. Based on these results, a reaction mechanism involving the surface hydroxyl groups (tbnd Casbnd OH) of the apatite and the carboxyl group of the acid was proposed.

  7. Phytogenic Feed Additives as an Alternative to Antibiotic Growth Promoters in Broiler Chickens

    PubMed Central

    Murugesan, Ganapathi Raj; Syed, Basharat; Haldar, Sudipto; Pender, Chasity

    2015-01-01

    The recent trend toward reduction of antibiotic growth promoters (AGP) in North American poultry diets has put tremendous pressure on the industry to look for viable alternatives. In this context, phytogenic feed additives (PFA) are researched to improve gut health and thereby performance. An experiment was conducted with the objective to evaluate the effects of PFA as an alternative to AGP on small intestinal histomorphology, cecal microbiota composition, nutrient digestibility, and growth performance in broiler chickens. A total of 432-day-old Vencobb 400 broiler chicks were randomly assigned to one of three dietary groups, each consisting of 12 replicate pens (n = 12 chicks/pen). The chicks were fed a corn–soybean meal-based control (CON), CON + 500 mg/kg of AGP (bacitracin methylene disalicylate containing 450 mg active BMD/g), or CON + 150 mg/kg of proprietary blend of PFA (Digestarom® Poultry) until 39 days of age when samples were collected. Birds fed either AGP or PFA had increased villus height in all three segments of the small intestine in comparison to the birds fed CON (P ≤ 0.05). Furthermore, the PFA-fed birds had significantly increased villus height and lower crypt depth compared to AGP fed birds (P ≤ 0.05). Birds fed either additive also had increased total tract digestibility of dry matter, crude protein, and ether extract (P ≤ 0.05). The strong effect of the PFA on villus height in the jejunum may suggest augmented nutrient absorption in PFA-fed birds. Although both additives reduced total cecal counts of anaerobic bacteria and Clostridium spp., PFA alone reduced the total coliform count while increasing the Lactobacillus spp. count (P ≤ 0.05). These results suggest the establishment of beneficial microbial colonies in PFA-fed birds. Overall, both PFA and AGP increased body weight gain while lowering the feed conversion ratio (P ≤ 0.05). Hence data from this experiment demonstrate the efficacy

  8. Propagation Effects and Circuit Performance of Modern Military Radio Systems with Particular Emphasis on those Employing Bandspreading Held in Arcueil (Paris) France 17-21 October 1988

    DTIC Science & Technology

    1989-12-01

    probabilit6 de fausse alarme ( Pfa ) lorsque le signal nest pas pr~sent. Le coupiePnd, Pfa perrnet de comparer entre elles les diff6rentes hypoth~ses de...detection of initial sync is required to qualify possible bit slips. The frame acceptance probability PFA , frame rejection probability PFR, frame...a bit slip and those not, represented by PFBS and PFA respectively in Figure 3a. With a frame represented by two halves, the possible outcome may be

  9. Factor Analysis of Intern Effectiveness

    ERIC Educational Resources Information Center

    Womack, Sid T.; Hannah, Shellie Louise; Bell, Columbus David

    2012-01-01

    Four factors in teaching intern effectiveness, as measured by a Praxis III-similar instrument, were found among observational data of teaching interns during the 2010 spring semester. Those factors were lesson planning, teacher/student reflection, fairness & safe environment, and professionalism/efficacy. This factor analysis was as much of a…

  10. 2007 Chemical Biological Information Systems

    DTIC Science & Technology

    2007-01-11

    2 ] • P2|1 = P2 and P1|2 = P1 only if sensors are uncorrelated • Define correlation metric ρ – Note: Sensors with different PD & PFA can not have...sensing Sensor 1 AND 2, correlated sensing • Sensor 1: PD = 0.999, PFA = 0.4 • Sensor 2: PD = 0.99, PFA = 0.1 ρ = 0.25 ρ = 1.0 • Sensor 1: PD...0.999, PFA = 0.4 • Sensor 2: PD = 0.99, PFA = 0.1 • Prior Probability of Attack = 10-4 B a y e s i a n C o n f i d e n c e i n a t t a c k 0 0.1

  11. Robust Bayesian Factor Analysis

    ERIC Educational Resources Information Center

    Hayashi, Kentaro; Yuan, Ke-Hai

    2003-01-01

    Bayesian factor analysis (BFA) assumes the normal distribution of the current sample conditional on the parameters. Practical data in social and behavioral sciences typically have significant skewness and kurtosis. If the normality assumption is not attainable, the posterior analysis will be inaccurate, although the BFA depends less on the current…

  12. Paraformaldehyde fixation of neutrophils for immunolabeling of granule antigens in cryoultrasections.

    PubMed

    Elliott, E; Dennison, C; Fortgens, P H; Travis, J

    1995-10-01

    Paraformaldehyde (PFA) fixation was optimized to facilitate the immobilization and labeling of multiple granule antigens, using short fixation regimens and cryoultramicrotomy of unembedded neutrophils (PMNs). In the optimal protocol, extraction of azurophil granule antigens (especially of the abundant elastase) was obviated by manipulating the polymeric state of PFA, and hence its rate of cross-linking, by altering its concentration and pH in a multistep process. Primary fixation conditions used (4% PFA, pH 8.0, 5 min) favor fixative penetration and rapid cross-linking. Stable cross-linking of the antigen was achieved in a secondary fixation step using conditions that favor larger, more cross-linking polymeric forms of PFA (8% PFA, pH 7.2, 15 min). Immobilization of granule antigens was enhanced by flotation of cut sections on fixative (8% PFA, pH 8.0) before labeling and by using post-labeling fixation with 1% glutaraldehyde. The optimized protocol facilitated immobilization and immunolabeling of elastase, myeloperoxidase, lactoferrin, and cathepsin D in highly hydrated, unembedded PMNs.

  13. Outcomes of dysvascular partial foot amputation and how these compare to transtibial amputation: a systematic review for the development of shared decision-making resources.

    PubMed

    Dillon, Michael P; Quigley, Matthew; Fatone, Stefania

    2017-03-14

    and ipsilateral reamputation where data allowed for proportional meta-analyses. Twenty-nine unique articles were included in the review, acknowledging that some studies reported multiple outcomes. Eighteen studies reported all-cause proportionate mortality. A smaller number of studies reported outcomes related to functional ability (two), mobility (four), quality of life (three), ipsilateral reamputation (six) as well as wound healing and complications (four). No studies related to pain, participation or psychosocial outcomes met the inclusion criteria. Subjects were typically older and male and had diabetes among other comorbidities. More detailed information about the cohorts such as race or sociodemographic factors were reported in an ad hoc manner. Common sources of bias included contamination, co-intervention, or lack of operational definition for some outcomes (e.g., wound healing) as illustrative examples. Aside from mortality, there was limited evidence regarding outcomes of dysvascular PFA, particularly how outcomes differ between levels of PFA and TTA. Acknowledging that there is considerable uncertainty given the small body of literature on many topics where the risk of bias is high, the available evidence suggests that a large proportion of people with PFA experience delayed wound healing and ipsilateral reamputation. People with TTA have increased risk of mortality compared to those with PFA, which may reflect that those considered suitable candidates for TTA have more advanced systemic disease that also increases the risk of dying. Mobility and quality of life may be similar in people with PFA and TTA. CRD42015029186.

  14. The Infinitesimal Jackknife with Exploratory Factor Analysis

    ERIC Educational Resources Information Center

    Zhang, Guangjian; Preacher, Kristopher J.; Jennrich, Robert I.

    2012-01-01

    The infinitesimal jackknife, a nonparametric method for estimating standard errors, has been used to obtain standard error estimates in covariance structure analysis. In this article, we adapt it for obtaining standard errors for rotated factor loadings and factor correlations in exploratory factor analysis with sample correlation matrices. Both…

  15. Assessment methods for aspirin-mediated platelet antiaggregation in type 2 diabetic patients: degree of correlation between 2 point-of-care methods.

    PubMed

    Cubero Gómez, Jose M; Navarro Puerto, María A; Acosta Martínez, Juan; De Mier Barragán, María I; Pérez Santigosa, Pastor L; Sánchez Burguillos, Francisco; Molano Casimiro, Francisco; Pastor Torres, Luis

    2014-07-01

    Impaired response to antiplatelet therapy in diabetic patients results in a higher incidence of drug-eluting stent thrombosis. This study determined the prevalence of high on-aspirin (AS) platelet reactivity in type 2 diabetic patients treated with percutaneous coronary intervention (PCI) using the VerifyNow Aspirin Assay (VN) and platelet function analyzer PFA-100 (PFA-100) and analyzed the correlation between both methods. Type 2 diabetic patients (100) with non-ST-elevation acute coronary syndrome who underwent PCI and Xience V drug-eluting stent implantation were included in this study. After PCI, platelet antiaggregation mediated by acetylsalicylic acid was assessed by VN and PFA-100. The degree of correlation and concordance was then determined. When assayed with VN, 7% of the patients were nonresponders to aspirin (aspirin reaction units >550), and when assayed with PFA-10, 41% were nonresponders (closure time <193 seconds). Of the patients, 4% were nonresponders to aspirin according to VN but were sensitive to aspirin according to PFA-100, and 38% were sensitive to aspirin according to VN and nonresponders according to PFA-100. Overall, 55% of the patients were aspirin-sensitive in both methods. The Spearman's coefficient between VN and PFA-100 results was r = 0.09 (P = 0.35). The kappa index value was 0.0062 (P = 0.91). There is no concordance or correlation between the VN and PFA-100 results. Therefore, the use of these analyses should be restricted to clinical research, which limits its application in clinical practice.

  16. Factor Retention in Exploratory Factor Analysis: A Comparison of Alternative Methods.

    ERIC Educational Resources Information Center

    Mumford, Karen R.; Ferron, John M.; Hines, Constance V.; Hogarty, Kristine Y.; Kromrey, Jeffery D.

    This study compared the effectiveness of 10 methods of determining the number of factors to retain in exploratory common factor analysis. The 10 methods included the Kaiser rule and a modified Kaiser criterion, 3 variations of parallel analysis, 4 regression-based variations of the scree procedure, and the minimum average partial procedure. The…

  17. Exploratory factor analysis in Rehabilitation Psychology: a content analysis.

    PubMed

    Roberson, Richard B; Elliott, Timothy R; Chang, Jessica E; Hill, Jessica N

    2014-11-01

    Our objective was to examine the use and quality of exploratory factor analysis (EFA) in articles published in Rehabilitation Psychology. Trained raters examined 66 separate exploratory factor analyses in 47 articles published between 1999 and April 2014. The raters recorded the aim of the EFAs, the distributional statistics, sample size, factor retention method(s), extraction and rotation method(s), and whether the pattern coefficients, structure coefficients, and the matrix of association were reported. The primary use of the EFAs was scale development, but the most widely used extraction and rotation method was principle component analysis, with varimax rotation. When determining how many factors to retain, multiple methods (e.g., scree plot, parallel analysis) were used most often. Many articles did not report enough information to allow for the duplication of their results. EFA relies on authors' choices (e.g., factor retention rules extraction, rotation methods), and few articles adhered to all of the best practices. The current findings are compared to other empirical investigations into the use of EFA in published research. Recommendations for improving EFA reporting practices in rehabilitation psychology research are provided.

  18. Pressure-flow characteristics of normal and disordered esophageal motor patterns.

    PubMed

    Singendonk, Maartje M J; Kritas, Stamatiki; Cock, Charles; Ferris, Lara F; McCall, Lisa; Rommel, Nathalie; van Wijk, Michiel P; Benninga, Marc A; Moore, David; Omari, Taher I

    2015-03-01

    To perform pressure-flow analysis (PFA) in a cohort of pediatric patients who were referred for diagnostic manometric investigation. PFA was performed using purpose designed Matlab-based software. The pressure-flow index (PFI), a composite measure of bolus pressurization relative to flow and the impedance ratio, a measure of the extent of bolus clearance failure were calculated. Tracings of 76 pediatric patients (32 males; 9.1 ± 0.7 years) and 25 healthy adult controls (7 males; 36.1 ± 2.2 years) were analyzed. Patients mostly had normal motility (50%) or a category 4 disorder and usually weak peristalsis (31.5%) according to the Chicago Classification. PFA of healthy controls defined reference ranges for PFI ≤142 and impedance ratio ≤0.49. Pediatric patients with pressure-flow (PF) characteristics within these limits had normal motility (62%), most patients with PF characteristics outside these limits also had an abnormal Chicago Classification (61%). Patients with high PFI and disordered motor patterns all had esophagogastric junction outflow obstruction. Disordered PF characteristics are associated with disordered esophageal motor patterns. By defining the degree of over-pressurization and/or extent of clearance failure, PFA may be a useful adjunct to esophageal pressure topography-based classification. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Perceptions of psychological first aid among providers responding to Hurricanes Gustav and Ike.

    PubMed

    Allen, Brian; Brymer, Melissa J; Steinberg, Alan M; Vernberg, Eric M; Jacobs, Anne; Speier, Anthony H; Pynoos, Robert S

    2010-08-01

    Psychological First Aid (PFA), developed by the National Child Traumatic Stress Network and the Department of Veterans Affairs National Center for Posttraumatic Stress Disorder, has been widely disseminated both nationally and internationally, and adopted and used by a number of disaster response organizations and agencies after major catastrophic events across the United States. This study represents a first examination of the perceptions of providers who utilized PFA in response to a disaster. Study participants included 50 individuals who utilized PFA in their response to Hurricane Gustav or Ike. Findings indicated that participation in PFA training was perceived to increase confidence in working with adults and children. PFA was not seen as harmful to survivors, and was perceived as an appropriate intervention for responding in the aftermath of hurricanes.

  20. Protein adsorption and cell adhesion controlled by the surface chemistry of binary perfluoroalkyl/oligo(ethylene glycol) self-assembled monolayers.

    PubMed

    Li, Shanshan; Yang, Dingyun; Tu, Haiyang; Deng, Hongtao; Du, Dan; Zhang, Aidong

    2013-07-15

    This work reports a study of protein adsorption and cell adhesion on binary self-assembled monolayers (SAMs) of alkanethiols with terminal perfluoroalkyl (PFA) and oligo(ethylene glycol) (OEG) chains in varying ratios. The surface chemistry of the SAMs was characterized by contact angle measurement, grazing angle infrared spectroscopy (GIR), X-ray photoelectron spectroscopy, and the effect on protein adsorption was investigated by surface plasmon resonance, GIR, and immunosorbent assay. Hela cell adhesion on these surfaces was also studied by fluorescence microscopy. Results reveal that, compared to OEG, PFA tended to be a higher fraction of the composition in SAM than in the assembly solution. More interestingly, the nearly 38% PFA SAM had a strong antifouling property whereas the 74% PFA SAM showed a high adsorption capacity to protein and cell. The binary PFA/OEG SAMs were favorable for maintaining the fibrinogen conformation, hence its high activity. The findings may have important implications for constructing PFA-containing surfaces with the distinct properties that is highly resistant or highly favorable toward protein adsorption and cell adhesion. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Domains of Pyrococcus furiosus L-asparaginase fold sequentially and assemble through strong intersubunit associative forces.

    PubMed

    Garg, Dushyant K; Tomar, Rachana; Dhoke, Reema R; Srivastava, Ankit; Kundu, Bishwajit

    2015-05-01

    Here, we report the folding and assembly of a Pyrococcus furiosus-derived protein, L-asparaginase (PfA). PfA functions as a homodimer, with each monomer made of distinct N- and C-terminal domains. The purified individual domains as well as single Trp mutant of each domain were subjected to chemical denaturation/renaturation and probed by combination of spectroscopic, chromatographic, quenching and scattering techniques. We found that the N-domain acts like a folding scaffold and assists the folding of remaining polypeptide. The domains displayed sequential folding with the N-domain having higher thermodynamic stability. We report that the extreme thermal stability of PfA is due to the presence of high intersubunit associative forces supported by extensive H-bonding and ionic interactions network. Our results proved that folding cooperativity in a thermophilic, multisubunit protein is dictated by concomitant folding and association of constituent domains directly into a native quaternary structure. This report gives an account of the factors responsible for folding and stability of a therapeutically and industrially important protein.

  2. Survivorship and functional outcomes of patellofemoral arthroplasty: a systematic review.

    PubMed

    van der List, J P; Chawla, H; Zuiderbaan, H A; Pearle, A D

    2017-08-01

    Historically poor results of survivorship and functional outcomes of patellofemoral arthroplasty (PFA) have been reported in the setting of isolated patellofemoral osteoarthritis. More recently, however, fairly good results of PFA were reported, but the current status of PFA outcomes is unknown. Therefore, a systematic review was performed to assess overall PFA survivorship and functional outcomes. A search was performed using PubMed, Embase and Cochrane systems, and the registries were searched. Twenty-three cohort studies and one registry reported survivorship using Kaplan-Meier curve, while 51 cohort studies reported functional outcomes of PFA. Twelve studies were level II studies, while 45 studies were level III or IV studies. Heterogeneity was mainly seen in type of prosthesis and year the cohort started. Nine hundred revisions in 9619 PFAs were reported yielding 5-, 10-, 15- and 20-year PFA survivorships of 91.7, 83.3, 74.9 and 66.6 %, respectively, and an annual revision rate of 2.18. Functional outcomes were reported in 2587 PFAs with an overall score of 82.2 % of the maximum score. KSS and Knee Function Score were 87.5 and 81.6 %, respectively. This systematic review showed that fairly good results of PFA survivorship and functional outcomes were reported at short- and midterm follow-up in the setting of isolated patellofemoral osteoarthritis. Heterogeneity existed mainly in prosthesis design and year the cohort started. These results provide a clear overview of the current status of PFA in the setting of isolated patellofemoral osteoarthritis. IV.

  3. A systematic literature search on psychological first aid: lack of evidence to develop guidelines.

    PubMed

    Dieltjens, Tessa; Moonens, Inge; Van Praet, Koen; De Buck, Emmy; Vandekerckhove, Philippe

    2014-01-01

    Providing psychological first aid (PFA) is generally considered to be an important element in preliminary care of disaster victims. Using the best available scientific basis for courses and educational materials, the Belgian Red Cross-Flanders wants to ensure that its volunteers are trained in the best way possible. To identify effective PFA practices, by systematically reviewing the evidence in existing guidelines, systematic reviews and individual studies. Systematic literature searches in five bibliographic databases (MEDLINE, PsycINFO, The Cochrane Library, PILOTS and G-I-N) were conducted from inception to July 2013. Five practice guidelines were included which were found to vary in the development process (AGREE II score 20-53%) and evidence base used. None of them provides solid evidence concerning the effectiveness of PFA practices. Additionally, two systematic reviews of PFA were found, both noting a lack of studies on PFA. A complementary search for individual studies, using a more sensitive search strategy, identified 11 237 references of which 102 were included for further full-text examination, none of which ultimately provides solid evidence concerning the effectiveness of PFA practices. The scientific literature on psychological first aid available to date, does not provide any evidence about the effectiveness of PFA interventions. Currently it is impossible to make evidence-based guidelines about which practices in psychosocial support are most effective to help disaster and trauma victims.

  4. Comparative evaluation of Plateletworks, Multiplate analyzer and Platelet function analyzer-200 in cardiology patients.

    PubMed

    Kim, Jeeyong; Cho, Chi Hyun; Jung, Bo Kyeung; Nam, Jeonghun; Seo, Hong Seog; Shin, Sehyun; Lim, Chae Seung

    2018-04-14

    The objective of this study was to comparatively evaluate three commercial whole-blood platelet function analyzer systems: Platelet Function Analyzer-200 (PFA; Siemens Canada, Mississauga, Ontario, Canada), Multiplate analyzer (MP; Roche Diagnostics International Ltd., Rotkreuz, Switzerland), and Plateletworks Combo-25 kit (PLW; Helena Laboratories, Beaumont, TX, USA). Venipuncture was performed on 160 patients who visited a department of cardiology. Pairwise agreement among the three platelet function assays was assessed using Cohen's kappa coefficient and percent agreement within the reference limit. Kappa values with the same agonists were poor between PFA-collagen (COL; agonist)/adenosine diphosphate (ADP) and MP-ADP (-0.147), PFA-COL/ADP and PLW-ADP (0.089), MP-ADP and PLW-ADP (0.039), PFA-COL/ADP and MP-COL (-0.039), and between PFA-COL/ADP and PLW-COL (-0.067). Nonetheless, kappa values for the same assay principle with a different agonist were slightly higher between PFA-COL/ADP and PFA-COL/EPI (0.352), MP-ADP and MP-COL (0.235), and between PLW-ADP and PLW-COL (0.247). The range of percent agreement values was 38.7% to 73.8%. Therefore, various measurements of platelet function by more than one method were needed to obtain a reliable interpretation of platelet function considering low kappa coefficient and modest percent agreement rates among 3 different platelet function tests.

  5. A single factor underlies the metabolic syndrome: a confirmatory factor analysis.

    PubMed

    Pladevall, Manel; Singal, Bonita; Williams, L Keoki; Brotons, Carlos; Guyer, Heidi; Sadurni, Josep; Falces, Carles; Serrano-Rios, Manuel; Gabriel, Rafael; Shaw, Jonathan E; Zimmet, Paul Z; Haffner, Steven

    2006-01-01

    Confirmatory factor analysis (CFA) was used to test the hypothesis that the components of the metabolic syndrome are manifestations of a single common factor. Three different datasets were used to test and validate the model. The Spanish and Mauritian studies included 207 men and 203 women and 1,411 men and 1,650 women, respectively. A third analytical dataset including 847 men was obtained from a previously published CFA of a U.S. population. The one-factor model included the metabolic syndrome core components (central obesity, insulin resistance, blood pressure, and lipid measurements). We also tested an expanded one-factor model that included uric acid and leptin levels. Finally, we used CFA to compare the goodness of fit of one-factor models with the fit of two previously published four-factor models. The simplest one-factor model showed the best goodness-of-fit indexes (comparative fit index 1, root mean-square error of approximation 0.00). Comparisons of one-factor with four-factor models in the three datasets favored the one-factor model structure. The selection of variables to represent the different metabolic syndrome components and model specification explained why previous exploratory and confirmatory factor analysis, respectively, failed to identify a single factor for the metabolic syndrome. These analyses support the current clinical definition of the metabolic syndrome, as well as the existence of a single factor that links all of the core components.

  6. Anthropometric data reduction using confirmatory factor analysis.

    PubMed

    Rohani, Jafri Mohd; Olusegun, Akanbi Gabriel; Rani, Mat Rebi Abdul

    2014-01-01

    The unavailability of anthropometric data especially in developing countries has remained a limiting factor towards the design of learning facilities with sufficient ergonomic consideration. Attempts to use anthropometric data from developed countries have led to provision of school facilities unfit for the users. The purpose of this paper is to use factor analysis to investigate the suitability of the collected anthropometric data as a database for school design in Nigerian tertiary institutions. Anthropometric data were collected from 288 male students in a Federal Polytechnic in North-West of Nigeria. Their age is between 18-25 years. Nine vertical anthropometric dimensions related to heights were collected using the conventional traditional equipment. Exploratory factor analysis was used to categorize the variables into a model consisting of two factors. Thereafter, confirmatory factor analysis was used to investigate the fit of the data to the proposed model. A just identified model, made of two factors, each with three variables was developed. The variables within the model accounted for 81% of the total variation of the entire data. The model was found to demonstrate adequate validity and reliability. Various measuring indices were used to verify that the model fits the data properly. The final model reveals that stature height and eye height sitting were the most stable variables for designs that have to do with standing and sitting construct. The study has shown the application of factor analysis in anthropometric data analysis. The study highlighted the relevance of these statistical tools to investigate variability among anthropometric data involving diverse population, which has not been widely used for analyzing previous anthropometric data. The collected data is therefore suitable for use while designing for Nigerian students.

  7. Comparisons of Exploratory and Confirmatory Factor Analysis.

    ERIC Educational Resources Information Center

    Daniel, Larry G.

    Historically, most researchers conducting factor analysis have used exploratory methods. However, more recently, confirmatory factor analytic methods have been developed that can directly test theory either during factor rotation using "best fit" rotation methods or during factor extraction, as with the LISREL computer programs developed…

  8. Bootstrap Standard Error Estimates in Dynamic Factor Analysis

    ERIC Educational Resources Information Center

    Zhang, Guangjian; Browne, Michael W.

    2010-01-01

    Dynamic factor analysis summarizes changes in scores on a battery of manifest variables over repeated measurements in terms of a time series in a substantially smaller number of latent factors. Algebraic formulae for standard errors of parameter estimates are more difficult to obtain than in the usual intersubject factor analysis because of the…

  9. NV PFA Regional Data

    DOE Data Explorer

    James Faulds

    2015-10-28

    This project focused on defining geothermal play fairways and development of a detailed geothermal potential map of a large transect across the Great Basin region (96,000 km2), with the primary objective of facilitating discovery of commercial-grade, blind geothermal fields (i.e. systems with no surface hot springs or fumaroles) and thereby accelerating geothermal development in this promising region. Data included in this submission consists of: structural settings (target areas, recency of faulting, slip and dilation potential, slip rates, quality), regional-scale strain rates, earthquake density and magnitude, gravity data, temperature at 3 km depth, permeability models, favorability models, degree of exploration and exploration opportunities, data from springs and wells, transmission lines and wilderness areas, and published maps and theses for the Nevada Play Fairway area.

  10. NV PFA - Steptoe Valley

    DOE Data Explorer

    Jim Faulds

    2015-10-29

    All datasets and products specific to the Steptoe Valley model area. Includes a packed ArcMap project (.mpk), individually zipped shapefiles, and a file geodatabase for the northern Steptoe Valley area; a GeoSoft Oasis montaj project containing GM-SYS 2D gravity profiles along the trace of our seismic reflection lines; a 3D model in EarthVision; spreadsheet of links to published maps; and spreadsheets of well data.

  11. How Factor Analysis Can Be Used in Classification.

    ERIC Educational Resources Information Center

    Harman, Harry H.

    This is a methodological study that suggests a taxometric technique for objective classification of yeasts. It makes use of the minres method of factor analysis and groups strains of yeast according to their factor profiles. The similarities are judged in the higher-dimensional space determined by the factor analysis, but otherwise rely on the…

  12. Opening Furan for Tailoring Properties of Bio-based Poly(Furfuryl Alcohol) Thermoset.

    PubMed

    Falco, Guillaume; Guigo, Nathanael; Vincent, Luc; Sbirrazzuoli, Nicolas

    2018-06-11

    This work shows how furan ring-opening reactions were controlled by polymerization conditions to tune the cross-link density in bio-based poly(furfuryl alcohol) (PFA). The influence of water and isopropyl alcohol (IPA) on the polymerization of furfuryl alcohol, and particularly on furan ring-opening, was investigated by means of 13 C NMR and FT-IR spectroscopy. Results indicated that formation of open structures were favored in the presence of solvents, thus leading to modification of the thermo-mechanical properties compared to PFA cross-linked without solvent. Dynamic mechanical analyses showed that when slightly more open structures were present in PFA it resulted in an important decrease of the cross-link density. Despite lower glass-transition temperature and lower elastic modulus for PFA polymerized with solvent, the thermal stability remains very high (>350 °C) even with more open structures in PFA. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Low Cost Fiber Optic Cable Assemblies for Local Distribution Systems

    DTIC Science & Technology

    1977-04-01

    coefficient of friction, and is chemically inert. PFA exhibits low water permeability and ab- sorption . FEP-100 and FEP-110 were initially extruded over T08...with FEP 110. To overcome these problems, Teflon PFA 9704 was evaluated. It exhibited good extrudability which allowed application of thin and thick...superior extrudability, in addition to meeting the optical characteristics required for a cladding material, Teflon PFA was considered a viable

  14. Evaluation of the Snap Sampler for Sampling Ground Water Monitoring Wells for VOCs and Explosives

    DTIC Science & Technology

    2007-08-01

    prevent losses due to sorption . The time needed for equilibration will depend on the sampling device (and the materials in the sampler), the physical...bottles contain a perfluoroalkoxy ( PFA ) Teflon-coated spring mechanism that is connected to PFA Teflon end caps at both ends of the bottles...materials: polyvinylidene fluoride (PVDF) Kynar tubing or PFA Teflon tubing. These samplers are deployed in the well with the end caps of the bottle

  15. Polyhydroxylated fatty alcohols derived from avocado suppress inflammatory response and provide non-sunscreen protection against UV-induced damage in skin cells.

    PubMed

    Rosenblat, Gennady; Meretski, Shai; Segal, Joseph; Tarshis, Mark; Schroeder, Avi; Zanin-Zhorov, Alexandra; Lion, Gilead; Ingber, Arieh; Hochberg, Malka

    2011-05-01

    Exposing skin to ultraviolet (UV) radiation contributes to photoaging and to the development of skin cancer by DNA lesions and triggering inflammatory and other harmful cellular cascades. The present study tested the ability of unique lipid molecules, polyhydroxylated fatty alcohols (PFA), extracted from avocado, to reduce UVB-induced damage and inflammation in skin. Introducing PFA to keratinocytes prior to their exposure to UVB exerted a protective effect, increasing cell viability, decreasing the secretion of IL-6 and PGE(2), and enhancing DNA repair. In human skin explants, treating with PFA reduced significantly UV-induced cellular damage. These results support the idea that PFA can play an important role as a photo-protective agent in UV-induced skin damage.

  16. Endovascular Management of the Arteria Profunda Femoralis: Long-Term Angiographic and Clinical Outcomes

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

    Karnabatidis, Dimitrios, E-mail: karnaby@med.upatras.gr; Spiliopoulos, Stavros; Pastromas, Georgios

    2012-10-15

    Purpose: This study was designed to investigate the long-term angiographic and clinical outcomes of percutaneous transluminal angioplasty (PTA) of the arteria profunda femoralis (PFA), in a series of patients suffering from critical limb ischemia (CLI) or severe intermittent claudication (IC). Methods: Our department's database was searched to identify patients who underwent PTA or bail-out stenting of the PFA. Among the study's inclusion criteria were Rutherford categories 3-6 and {>=}70% stenosis of the PFA. Only de novo stenotic lesions were assessed. Primary endpoints were technical success, angiographic lesion primary patency, angiographic binary in-lesion restenosis, and target lesion recanalization (TLR) rates. Secondarymore » endpoints included patient survival, limb salvage, and complication rates. Patient's baseline demographics, lesion, and procedural details were analyzed. Results: Between 2001 and 2011, 20 consecutive patients (17 males) with a mean age of 73 {+-} 9 (range 53-87) years underwent PTA or bail-out stenting in 23 PFA lesions. Critical limb ischemia was the indication in eight of 20 patients (40%). The mean lesion length was 31 {+-} 9.5 mm. The procedural technical success was 100% (23/23), whereas mean time angiographic and clinical follow-up was 26.8 {+-} 24.6 months. According to the Kaplan-Meier analysis, primary patency and binary restenosis rate were 95 and 86.1% respectively up to 8 years follow-up. No TLR procedures were performed. The 8-year patient survival and limb salvage rates were 87.5 and 84.7% respectively. Conclusions: PTA or stenting of focal, stenotic, PFA lesions, in patients suffering from CLI or IC, exhibit high long-term primary patency rates, as well as low binary restenosis and TLR rates. Large, multicenter studies are required to validate these results.« less

  17. Objective prediction of pharyngeal swallow dysfunction in dysphagia through artificial neural network modeling.

    PubMed

    Kritas, S; Dejaeger, E; Tack, J; Omari, T; Rommel, N

    2016-03-01

    Pharyngeal pressure-flow analysis (PFA) of high resolution impedance-manometry (HRIM) with calculation of the swallow risk index (SRI) can quantify swallow dysfunction predisposing to aspiration. We explored the potential use of artificial neural networks (ANN) to model the relationship between PFA swallow metrics and aspiration and to predict swallow dysfunction. Two hundred consecutive dysphagia patients referred for videofluoroscopy and HRIM were assessed. Presence of aspiration was scored and PFA software derived 13 metrics and the SRI. An ANN was created and optimized over training cycles to achieve optimal classification accuracy for matching inputs (PFA metrics) to output (presence of aspiration on videofluoroscopy). Application of the ANN returned a value between 0.00 and 1.00 reflecting the degree of swallow dysfunction. Twenty one patients were excluded due to insufficient number of swallows (<4). Of 179, 58 aspirated and 27 had aspiration pneumonia history. The SRI was higher in aspirators (aspiration 24 [9, 41] vs no aspiration 7 [2, 18], p < 0.001) and patients with pneumonia (pneumonia 27 [5, 42] vs no pneumonia 8 [3, 24], p < 0.05). The ANN Predicted Risk was higher in aspirators (aspiration 0.57 [0.38, 0.82] vs no aspiration 0.13 [0.4, 0.25], p < 0.001) and in patients with pneumonia (pneumonia 0.46 [0.18, 0.60] vs no pneumonia 0.18 [0.6, 0.49], p < 0.01). Prognostic value of the ANN was superior to the SRI. In a heterogeneous cohort of dysphagia patients, PFA with ANN modeling offers enhanced detection of clinically significant swallowing dysfunction, probably more accurately reflecting the complex interplay of swallow characteristics that causes aspiration. © 2016 John Wiley & Sons Ltd.

  18. Sustainable construction: composite use of tyres and ash in concrete.

    PubMed

    Snelson, D G; Kinuthia, J M; Davies, P A; Chang, S-R

    2009-01-01

    An investigation was carried out to establish the physical, mechanical and chemical characteristics of a non-standard (unprocessed) pulverised fuel ash (PFA) and waste tyres from a former landfill site at the Power Station Hill near Church Village, South Wales, United Kingdom. Investigations are on-going to establish the suitability of the fly ash and/or tyres in road construction (embankment and pavement) and also in concrete to be used in the construction of the proposed highway. This paper reports on concrete-based construction where concrete blends (using various levels of PFA as partial replacement for Portland cement (PC), and shredded waste tyres (chips 15-20mm) as aggregate replacement) were subjected to unconfined compressive strength tests to establish performance, hence, optimising mix designs. Strength development up to 180 days for the concrete made with PC-PFA blends as binders (PC-PFA concrete), with and without aggregate replacement with tyre chips, is reported. The binary PC-PFA concrete does not have good early strength but tends to improve at longer curing periods. The low early strength observed means that PC-PFA concrete cannot be used for structures, hence, only as low to medium strength applications such as blinding, low-strength foundations, crash barriers, noise reduction barriers, cycle paths, footpaths and material for pipe bedding.

  19. A Review of CEFA Software: Comprehensive Exploratory Factor Analysis Program

    ERIC Educational Resources Information Center

    Lee, Soon-Mook

    2010-01-01

    CEFA 3.02(Browne, Cudeck, Tateneni, & Mels, 2008) is a factor analysis computer program designed to perform exploratory factor analysis. It provides the main properties that are needed for exploratory factor analysis, namely a variety of factoring methods employing eight different discrepancy functions to be minimized to yield initial…

  20. Surface-Cycling of Rhenium and its Isotopes

    DTIC Science & Technology

    2009-06-01

    Fisher Scientific) in the WHOI plasma facility. Samples were introduced using a PFA MicroFlow nebulizer (Elemental Scientific Incorporated), a quartz...Samples were introduced using a PFA MicroFlow nebulizer (Elemental Scientific Incorporated), a quartz spray chamber, and regular cones. Analyses are done in...189Os. Samples dissolved in 1 mL of 0.5 molL−1 HNO3 are introduced using a PFA MicroFlow nebulizer (Elemental Scientific Incorporated), a quartz spray

  1. Physics Metacognition Inventory Part II: Confirmatory factor analysis and Rasch analysis

    NASA Astrophysics Data System (ADS)

    Taasoobshirazi, Gita; Bailey, MarLynn; Farley, John

    2015-11-01

    The Physics Metacognition Inventory was developed to measure physics students' metacognition for problem solving. In one of our earlier studies, an exploratory factor analysis provided evidence of preliminary construct validity, revealing six components of students' metacognition when solving physics problems including knowledge of cognition, planning, monitoring, evaluation, debugging, and information management. The college students' scores on the inventory were found to be reliable and related to students' physics motivation and physics grade. However, the results of the exploratory factor analysis indicated that the questionnaire could be revised to improve its construct validity. The goal of this study was to revise the questionnaire and establish its construct validity through a confirmatory factor analysis. In addition, a Rasch analysis was applied to the data to better understand the psychometric properties of the inventory and to further evaluate the construct validity. Results indicated that the final, revised inventory is a valid, reliable, and efficient tool for assessing student metacognition for physics problem solving.

  2. Stability validation of paraformaldehyde-fixed samples for the assessment of the platelet PECAM-1, P-selectin, and PAR-1 thrombin receptor by flow cytometry.

    PubMed

    Atar, Oliver D; Eisert, Christian; Pokov, Ilya; Serebruany, Victor L

    2010-07-01

    Sample fixation for storage and/or transportation represents an unsolved challenge for multicenter clinical trials assessing serial changes in platelet activity, or monitoring various antiplatelet regimens. Whole blood flow cytometry represents a major advance in defining platelet function, although special training and expensive equipment is required. We sought to determine how fixation with 2% paraformaldehyde (PFA), and storage of blood samples over 1 week affects the flow cytometry readings for both intact and thrombin-activating four major surface platelet receptors. Whole blood platelet expression of PECAM-1, P-selectin, PAR-1 inactive receptor (SPAN-12), and cleaved (WEDE-15) epitope was assessed immediately after blood draw, after staining with 2% PFA, and at day 1, 3, 5, and 7. The study was performed in 6 volunteers with multiple risk factors for vascular disease, not receiving any antiplatelet agents. Staining with PFA resulted in a slight decrease of fluorescence intensity, especially for PECAM-1, while antigen expression at day 1, 3 and 5 remains consistent, and highly reproducible. At day 7 there was a small but inconsistent trend towards diminished fluorescence intensity. The platelet data were consistent while validated with the isotype-matched irrelevant antibody. These data suggest that there is a 5 day window to perform final flow cytometry readings of whole blood PFA-fixed inactivated platelet samples. In contrast, thrombin activation cause gradual loss of flow cytometry signal, and cannot be recommended for long-term storage. This is critical logistic information for conducting multicenter platelet substudies within the framework of major clinical trials.

  3. Omega-3 fatty acids in the gravid pig uterus as affected by maternal supplementation with omega-3 fatty acids.

    PubMed

    Brazle, A E; Johnson, B J; Webel, S K; Rathbun, T J; Davis, D L

    2009-03-01

    Two experiments evaluated the ability of maternal fatty acid supplementation to alter conceptus and endometrial fatty acid composition. In Exp. 1, treatments were 1) the control, a corn-soybean meal diet; 2) flax, the control diet plus ground flax (3.75% of diet); and 3) protected fatty acids (PFA), the control plus a protected fish oil source rich in n-3 PUFA (Gromega, JBS United Inc., Sheridan, IN; 1.5% of diet). Supplements replaced equal parts of corn and soybean meal. When gilts reached 170 d of age, PG600 (PMSG and hCG, Intervet USA, Millsboro, DE) was injected to induce puberty, and dietary treatments (n = 8/treatment) were initiated. When detected in estrus, gilts were artificially inseminated. On d 40 to 43 of gestation, 7 gilts in the control treatment, 8 gilts in the PFA treatment, and 5 gilts in the flax treatment were pregnant and were slaughtered. Compared with the control treatment, the flax treatment tended to increase eicosapentaenoic acid (EPA: C20:5n-3) in fetuses (0.14 vs. 0.25 +/- 0.03 mg/g of dry tissue; P = 0.055), whereas gilts receiving PFA had more (P < 0.05) docosahexaenoic acid (DHA: C22:6n-3) in their fetuses (5.23 vs. 4.04 +/- 0.078 mg/g) compared with gilts fed the control diet. Both the flax and PFA diets increased (P < 0.05) DHA (0.60, 0.82, and 0.85 +/- 0.078 mg/g for the control, flax, and PFA diet, respectively) in the chorioallantois. In the endometrium, EPA and docosapentaenoic acid (C22:5n-3) were increased by the flax diet (P < 0.001; P < 0.05), whereas gilts receiving PFA had increased DHA (P < 0.001). The flax diet selectively increased EPA, and the PFA diet selectively increased DHA in the fetus and endometrium. In Exp. 2, gilts were fed diets containing PFA (1.5%) or a control diet beginning at approximately 170 of age (n = 13/treatment). A blood sample was collected after 30 d of treatment, and gilts were artificially inseminated when they were approximately 205 d old. Conceptus and endometrial samples were collected on

  4. A comparison study on detection of key geochemical variables and factors through three different types of factor analysis

    NASA Astrophysics Data System (ADS)

    Hoseinzade, Zohre; Mokhtari, Ahmad Reza

    2017-10-01

    Large numbers of variables have been measured to explain different phenomena. Factor analysis has widely been used in order to reduce the dimension of datasets. Additionally, the technique has been employed to highlight underlying factors hidden in a complex system. As geochemical studies benefit from multivariate assays, application of this method is widespread in geochemistry. However, the conventional protocols in implementing factor analysis have some drawbacks in spite of their advantages. In the present study, a geochemical dataset including 804 soil samples collected from a mining area in central Iran in order to search for MVT type Pb-Zn deposits was considered to outline geochemical analysis through various fractal methods. Routine factor analysis, sequential factor analysis, and staged factor analysis were applied to the dataset after opening the data with (additive logratio) alr-transformation to extract mineralization factor in the dataset. A comparison between these methods indicated that sequential factor analysis has more clearly revealed MVT paragenesis elements in surface samples with nearly 50% variation in F1. In addition, staged factor analysis has given acceptable results while it is easy to practice. It could detect mineralization related elements while larger factor loadings are given to these elements resulting in better pronunciation of mineralization.

  5. Job compensable factors and factor weights derived from job analysis data.

    PubMed

    Chi, Chia-Fen; Chang, Tin-Chang; Hsia, Ping-Ling; Song, Jen-Chieh

    2007-06-01

    Government data on 1,039 job titles in Taiwan were analyzed to assess possible relationships between job attributes and compensation. For each job title, 79 specific variables in six major classes (required education and experience, aptitude, interest, work temperament, physical demands, task environment) were coded to derive the statistical predictors of wage for managers, professionals, technical, clerical, service, farm, craft, operatives, and other workers. Of the 79 variables, only 23 significantly related to pay rate were subjected to a factor and multiple regression analysis for predicting monthly wages. Given the heterogeneous nature of collected job titles, a 4-factor solution (occupational knowledge and skills, human relations skills, work schedule hardships, physical hardships) explaining 43.8% of the total variance but predicting only 23.7% of the monthly pay rate was derived. On the other hand, multiple regression with 9 job analysis items (required education, professional training, professional certificate, professional experience, coordinating, leadership and directing, demand on hearing, proportion of shift working indoors, outdoors and others, rotating shift) better predicted pay and explained 32.5% of the variance. A direct comparison of factors and subfactors of job evaluation plans indicated mental effort and responsibility (accountability) had not been measured with the current job analysis data. Cross-validation of job evaluation factors and ratings with the wage rates is required to calibrate both.

  6. A Physical Model of Human Skin and Its Application for Search and Rescue

    DTIC Science & Technology

    2009-12-01

    allow iv for the development of skin detection algorithms with a high probability of detection (PD) and a low probability of false alarm ( PFA ). The...various skin colors were collected. The skin detection algorithm developed in this work had a PD as high as 0.95 with a PFA of 0.006. Skin...threshold 0 < γ < 1. . . . . . . . . . . . . 103 63. Top: Detection Image with NDSI threshold γ = 0.314 with PD = 0.95 and corresponding PFA = 0.0156

  7. Development of Nanomedicines for Treatment of Posttraumatic Osteoarthritis

    DTIC Science & Technology

    2016-03-01

    explants fixed in PFA and paraffin-embedded showed positive signal in P-Dex-Alexa groups (with high background in the PBS control groups), which validate...addition (IL1beta-treated group not shown). Fluorescence images of samples after PBS washes and before PFA fixation are shown in (B) and (E) for P-Alexa...647 and Control groups, respectively. Representative fluorescence images of samples after PFA fixation and washes are shown in (C) and (F) for P

  8. A Pilot Study Evaluating the Feasibility of Psychological First Aid for Nursing Home Residents.

    PubMed

    Brown, Lisa M; Bruce, Martha L; Hyer, Kathryn; Mills, Whitney L; Vongxaiburana, Elizabeth; Polivka-West, Lumarie

    2009-07-01

    OBJECTIVES: The objectives of the pilot study were to modify existing psychological first aid (PFA) materials so they would be appropriate for use with institutionalized elders, evaluate the feasibility of using nursing home staff to deliver the intervention to residents, and solicit feedback from residents about the intervention. The STORM Study, an acronym for "services for treating older residents' mental health", is the first step in the development of an evidence-based disaster mental health intervention for this vulnerable and underserved population. METHOD: Demographic characteristics were collected on participating residents and staff. Program evaluation forms were completed by staff participants during the pilot test and nurse training session. Staff and resident discussion groups were conducted during the pilot test to collect qualitative data on the use of PFA in nursing homes. RESULTS: Results demonstrate the feasibility of the PFA program to train staff to provide residents with PFA during disasters. CONCLUSIONS: Future research should focus on whether PFA improves coping and reduces stress in disaster exposed nursing home residents.

  9. Chemical disinfection of combined sewer overflow waters using performic acid or peracetic acids.

    PubMed

    Chhetri, Ravi Kumar; Thornberg, Dines; Berner, Jesper; Gramstad, Robin; Öjstedt, Ulrik; Sharma, Anitha Kumari; Andersen, Henrik Rasmus

    2014-08-15

    We investigated the possibility of applying performic acid (PFA) and peracetic acid (PAA) for disinfection of combined sewer overflow (CSO) in existing CSO management infrastructures. The disinfection power of PFA and PAA towards Escherichia coli (E. coli) and Enterococcus was studied in batch-scale and pre-field experiments. In the batch-scale experiment, 2.5 mg L(-1) PAA removed approximately 4 log unit of E. coli and Enterococcus from CSO with a 360 min contact time. The removal of E. coli and Enterococcus from CSO was always around or above 3 log units using 2-4 mg L(-1) PFA; with a 20 min contact time in both batch-scale and pre-field experiments. There was no toxicological effect measured by Vibrio fischeri when CSO was disinfected with PFA; a slight toxic effect was observed on CSO disinfected with PAA. When the design for PFA based disinfection was applied to CSO collected from an authentic event, the disinfection efficiencies were confirmed and degradation rates were slightly higher than predicted in simulated CSO. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Durability of recycled aggregate concrete using pozzolanic materials.

    PubMed

    Ann, K Y; Moon, H Y; Kim, Y B; Ryou, J

    2008-01-01

    In this study, pulverized fuel ash (PFA) and ground granulated blast furnace slag (GGBS) were used to compensate for the loss of strength and durability of concrete containing recycled aggregate. As a result, 30% PFA and 65% GGBS concretes increased the compressive strength to the level of control specimens cast with natural granite gravel, but the tensile strength was still lowered at 28 days. Replacement with PFA and GGBS was effective in raising the resistance to chloride ion penetrability into the concrete body, measured by a rapid chloride ion penetration test based on ASTM C 1202-91. It was found that the corrosion rate of 30% PFA and 65% GGBS concretes was kept at a lower level after corrosion initiation, compared to the control specimens, presumably due to the restriction of oxygen and water access. However, it was less effective in increasing the chloride threshold level for steel corrosion. Hence, it is expected that the corrosion time for 30% PFA and 65% GGBS concrete containing recycled aggregate mostly equates to the corrosion-free life of control specimens.

  11. Using BMDP and SPSS for a Q factor analysis.

    PubMed

    Tanner, B A; Koning, S M

    1980-12-01

    While Euclidean distances and Q factor analysis may sometimes be preferred to correlation coefficients and cluster analysis for developing a typology, commercially available software does not always facilitate their use. Commands are provided for using BMDP and SPSS in a Q factor analysis with Euclidean distances.

  12. Climate smart agriculture, farm household typologies and food security: An ex-ante assessment from Eastern India.

    PubMed

    Lopez-Ridaura, Santiago; Frelat, Romain; van Wijk, Mark T; Valbuena, Diego; Krupnik, Timothy J; Jat, M L

    2018-01-01

    One of the great challenges in agricultural development and sustainable intensification is the assurance of social equity in food security oriented interventions. Development practitioners, researchers, and policy makers alike could benefit from prior insight into what interventions or environmental shocks might differentially affect farmers' food security status, in order to move towards more informed and equitable development. We examined the food security status and livelihood activities of 269 smallholder farm households (HHs) in Bihar, India. Proceeding with a four-step analysis, we first applied a multivariate statistical methodology to differentiate five primary farming system types. We next applied an indicator of food security in the form of HH potential food availability (PFA), and examined the contribution of crop, livestock, and on- and off-farm income generation to PFA within each farm HH type. Lastly, we applied scenario analysis to examine the potential impact of the adoption of 'climate smart' agricultural (CSA) practices in the form of conservation agriculture (CA) and improved livestock husbandry, and environmental shocks on HH PFA. Our results indicate that compared to livestock interventions, CA may hold considerable potential to boost HH PFA, though primarily for wealthier and medium-scale cereal farmers. These farm HH types were however considerably more vulnerable to food insecurity risks resulting from simulated drought, while part-time farmers and resource-poor agricultural laborers generating income from off-farm pursuits were comparatively less vulnerable, due in part to their more diversified income sources and potential to migrate in search of work. Our results underscore the importance of prior planning for development initiatives aimed at increasing smallholder food security while maintaining social equity, while providing a robust methodology to vet the implications of agricultural interventions on an ex ante basis.

  13. Sustainable construction: Composite use of tyres and ash in concrete

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

    Snelson, D.G.; Kinuthia, J.M.; Davies, P.A.

    2009-01-15

    An investigation was carried out to establish the physical, mechanical and chemical characteristics of a non-standard (unprocessed) pulverised fuel ash (PFA) and waste tyres from a former landfill site at the Power Station Hill near Church Village, South Wales, United Kingdom. Investigations are on-going to establish the suitability of the fly ash and/or tyres in road construction (embankment and pavement) and also in concrete to be used in the construction of the proposed highway. This paper reports on concrete-based construction where concrete blends (using various levels of PFA as partial replacement for Portland cement (PC), and shredded waste tyres (chipsmore » 15-20 mm) as aggregate replacement) were subjected to unconfined compressive strength tests to establish performance, hence, optimising mix designs. Strength development up to 180 days for the concrete made with PC-PFA blends as binders (PC-PFA concrete), with and without aggregate replacement with tyre chips, is reported. The binary PC-PFA concrete does not have good early strength but tends to improve at longer curing periods. The low early strength observed means that PC-PFA concrete cannot be used for structures, hence, only as low to medium strength applications such as blinding, low-strength foundations, crash barriers, noise reduction barriers, cycle paths, footpaths and material for pipe bedding.« less

  14. Likelihood-Based Confidence Intervals in Exploratory Factor Analysis

    ERIC Educational Resources Information Center

    Oort, Frans J.

    2011-01-01

    In exploratory or unrestricted factor analysis, all factor loadings are free to be estimated. In oblique solutions, the correlations between common factors are free to be estimated as well. The purpose of this article is to show how likelihood-based confidence intervals can be obtained for rotated factor loadings and factor correlations, by…

  15. A qualitative analysis of barriers, challenges, and successes in meeting the needs of Hurricane Katrina evacuee families.

    PubMed

    Legerski, John-Paul; Vernberg, Eric M; Noland, Brian J

    2012-12-01

    Hurricane Katrina caused many individuals to evacuate to towns and cities throughout the United States. Psychological First Aid (PFA) is a treatment program designed to help clinicians and other disaster relief workers address the needs of adults, youth, and families immediately following disasters. We conducted focus groups with disaster relief and evacuee service providers in the Kansas City Metro Area as an exploratory study to identify their perceptions of the needs of evacuees. Participants identified a number of mental health needs, as well as displacement-related challenges, including loss of social support, material loss, unemployment, and other stressful life events that were secondary to the hurricane. Many of these needs are consistent with principles presented in the PFA manual. We also found that service providers faced unique challenges when attempting to assist evacuees. We discuss implications of these findings for treatment programs and provide suggestions for addressing barriers to care.

  16. Exploring the Moderating Role of Perceived Flexibility Advantages in Mobile Learning Continuance Intention (MLCI)

    ERIC Educational Resources Information Center

    Huang, Rui-Ting; Hsiao, Chia-Hua; Tang, Tzy-Wen; Lien, Tsung-Cheng

    2014-01-01

    The primary purpose of this study was to explore the key factors that could affect mobile learning continuance intention (MLCI), and examine the moderating effect of perceived flexibility advantages (PFA) on the relationship between key mobile learning elements and continuance intention. Five hundred undergraduate students who had previously…

  17. Corrosion Chemistry in Inhibited HDA.

    DTIC Science & Technology

    1980-11-30

    mg HF. 200 B.1 Teflon PFA Reactor 201 (xviii) .. .. - i LIST OF MICROGRAPHS Micrograph Follows Page 4.1 A1/HDA x 1,000 80 4.2 A1/0.4 Wt % PF5 x 2,000...Ethylene Propylene copolymer Teflon PTFE Polytetrafluoroethylene Teflon PFA Perfluoroalkoxy fluorocarbon resin Spectroscopy IR (ir) Infra-red UV...fluoroplastic apparatus (to avoid any possible contamination by the reaction products of HF with glass). Iron powder (0.3g) was placed in a PFA screw-cap

  18. Suicide Inhibitors of Reverse Transcriptase in the Therapy of AIDS and Other Retroviruses

    DTIC Science & Technology

    1990-07-01

    I and 10 nanonolar) and compared to the E . Coli recombinant HIV-RT (Kindly donated by Dr. Steven Hughes Fort Detrick M.D.) and the wild type HIV-RT...Both the wild type and E . Coli HIV-RT’s were resistant to PFA showing essentially no inhibition at the lOnM level. Previous studies have shown that...10 nanomolar PFA. j, Sentivitv of Recombinant HIV-Reverse Transcriotase to Foscarnet. RECOMBINANT HIV RT ( E . COLI) + FOSCARNET 350001R 300000 PFA .001

  19. Critical Review and Technology Assessments, 󈨟-󈨠

    DTIC Science & Technology

    1991-09-01

    EUTELCIC ALLOY 3. Pages 406-409 890900 WATER SORPTION IN EPOXY THIN FILMS MCMASTER, M.G. UC, ,ERKELEY.CA) TRANSACTIONS. 89.22 SOANE, Di. ,EEEJHMT. Vol...NATION, 21 228-002 PENETRATION THROUGH PFA TUBING AND Vol. S, No. 2, Pags ANTISTATIC PFATUBING 22-28 THIS COLUMN FOCUSES ON A STUIDY OF PFA AND...ANTISTATIC WFA TURING (SUPPLIED BY GALnlEK CORPORATION. CHAS•K MN). THE A.NTISATIC PFA .MATERIAL USED HAS A SURFACE RESISTIVIrY OF lOTO THE ELEVENTH POWER -10

  20. What School Psychologists Need to Know about Factor Analysis

    ERIC Educational Resources Information Center

    McGill, Ryan J.; Dombrowski, Stefan C.

    2017-01-01

    Factor analysis is a versatile class of psychometric techniques used by researchers to provide insight into the psychological dimensions (factors) that may account for the relationships among variables in a given dataset. The primary goal of a factor analysis is to determine a more parsimonious set of variables (i.e., fewer than the number of…

  1. Item Factor Analysis: Current Approaches and Future Directions

    ERIC Educational Resources Information Center

    Wirth, R. J.; Edwards, Michael C.

    2007-01-01

    The rationale underlying factor analysis applies to continuous and categorical variables alike; however, the models and estimation methods for continuous (i.e., interval or ratio scale) data are not appropriate for item-level data that are categorical in nature. The authors provide a targeted review and synthesis of the item factor analysis (IFA)…

  2. Q-Type Factor Analysis of Healthy Aged Men.

    ERIC Educational Resources Information Center

    Kleban, Morton H.

    Q-type factor analysis was used to re-analyze baseline data collected in 1957, on 47 men aged 65-91. Q-type analysis is the use of factor methods to study persons rather than tests. Although 550 variables were originally studied involving psychiatry, medicine, cerebral metabolism and chemistry, personality, audiometry, dichotic and diotic memory,…

  3. Ordinary portland cement based solidification of toxic wastes: The role of OPC reviewed

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

    Hills, C.D.; Sollars, C.J.; Perry, R.

    1993-01-01

    A mixed waste stream, which is commercially solidified, has been solidified in the laboratory using OPC and PFA (pulverized fly ash) in a variety of mix proportions. The solidified products have been subjected to calorimetric, physical and microstructural analysis. The heat of hydration for OPC/waste mixes showed that a progressive poisoning of normal hydration reactions occurred with increasing waste addition. Once poisoned OPC failed to act as a cement and was substituted by PFA and other products in this role. Strength development was found to be related to the heat of hydration; this suggests that conduction calorimetry could be usedmore » to determine the suitability of a particular waste for OPC based solidification.« less

  4. Text mining factor analysis (TFA) in green tea patent data

    NASA Astrophysics Data System (ADS)

    Rahmawati, Sela; Suprijadi, Jadi; Zulhanif

    2017-03-01

    Factor analysis has become one of the most widely used multivariate statistical procedures in applied research endeavors across a multitude of domains. There are two main types of analyses based on factor analysis: Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA). Both EFA and CFA aim to observed relationships among a group of indicators with a latent variable, but they differ fundamentally, a priori and restrictions made to the factor model. This method will be applied to patent data technology sector green tea to determine the development technology of green tea in the world. Patent analysis is useful in identifying the future technological trends in a specific field of technology. Database patent are obtained from agency European Patent Organization (EPO). In this paper, CFA model will be applied to the nominal data, which obtain from the presence absence matrix. While doing processing, analysis CFA for nominal data analysis was based on Tetrachoric matrix. Meanwhile, EFA model will be applied on a title from sector technology dominant. Title will be pre-processing first using text mining analysis.

  5. Mixture Factor Analysis for Approximating a Nonnormally Distributed Continuous Latent Factor with Continuous and Dichotomous Observed Variables

    ERIC Educational Resources Information Center

    Wall, Melanie M.; Guo, Jia; Amemiya, Yasuo

    2012-01-01

    Mixture factor analysis is examined as a means of flexibly estimating nonnormally distributed continuous latent factors in the presence of both continuous and dichotomous observed variables. A simulation study compares mixture factor analysis with normal maximum likelihood (ML) latent factor modeling. Different results emerge for continuous versus…

  6. Pseudoaneurysm of the Profunda Femoris Artery following Blunt Trauma Treated by Endovascular Coil Embolization: Review of Two Cases and Relevant Literature

    PubMed Central

    McNerney, Patrick; Kiproff, Paul

    2017-01-01

    Profunda femoris artery (PFA) pseudoaneurysm after blunt trauma without associated femur fracture is a rare occurrence. Most of the reported cases of PFA pseudoaneurysm in the English literature developed after penetrating trauma, surgical procedures, and femur fractures. We present two such cases following blunt trauma and without any associated long bone injury. After initial imaging failed to show any long bone fracture, CT angiography confirmed pseudoaneurysm of the branch of the PFA. Both patients were then treated with emergent coil embolization of the bleeding vessel. Pseudoaneurysms typically present late and signs of persistent hip pain, thigh swelling, presence of a pulsatile mass, and even unexplained anemia all may suggest the diagnosis. Recognition of PFA pseudoaneurysm requires high index of suspicion and is often difficult to diagnose clinically because of its location. PMID:28246563

  7. Common factor analysis versus principal component analysis: choice for symptom cluster research.

    PubMed

    Kim, Hee-Ju

    2008-03-01

    The purpose of this paper is to examine differences between two factor analytical methods and their relevance for symptom cluster research: common factor analysis (CFA) versus principal component analysis (PCA). Literature was critically reviewed to elucidate the differences between CFA and PCA. A secondary analysis (N = 84) was utilized to show the actual result differences from the two methods. CFA analyzes only the reliable common variance of data, while PCA analyzes all the variance of data. An underlying hypothetical process or construct is involved in CFA but not in PCA. PCA tends to increase factor loadings especially in a study with a small number of variables and/or low estimated communality. Thus, PCA is not appropriate for examining the structure of data. If the study purpose is to explain correlations among variables and to examine the structure of the data (this is usual for most cases in symptom cluster research), CFA provides a more accurate result. If the purpose of a study is to summarize data with a smaller number of variables, PCA is the choice. PCA can also be used as an initial step in CFA because it provides information regarding the maximum number and nature of factors. In using factor analysis for symptom cluster research, several issues need to be considered, including subjectivity of solution, sample size, symptom selection, and level of measure.

  8. NASA Structural Analysis Report on the American Airlines Flight 587 Accident - Local Analysis of the Right Rear Lug

    NASA Technical Reports Server (NTRS)

    Raju, Ivatury S; Glaessgen, Edward H.; Mason, Brian H; Krishnamurthy, Thiagarajan; Davila, Carlos G

    2005-01-01

    A detailed finite element analysis of the right rear lug of the American Airlines Flight 587 - Airbus A300-600R was performed as part of the National Transportation Safety Board s failure investigation of the accident that occurred on November 12, 2001. The loads experienced by the right rear lug are evaluated using global models of the vertical tail, local models near the right rear lug, and a global-local analysis procedure. The right rear lug was analyzed using two modeling approaches. In the first approach, solid-shell type modeling is used, and in the second approach, layered-shell type modeling is used. The solid-shell and the layered-shell modeling approaches were used in progressive failure analyses (PFA) to determine the load, mode, and location of failure in the right rear lug under loading representative of an Airbus certification test conducted in 1985 (the 1985-certification test). Both analyses were in excellent agreement with each other on the predicted failure loads, failure mode, and location of failure. The solid-shell type modeling was then used to analyze both a subcomponent test conducted by Airbus in 2003 (the 2003-subcomponent test) and the accident condition. Excellent agreement was observed between the analyses and the observed failures in both cases. From the analyses conducted and presented in this paper, the following conclusions were drawn. The moment, Mx (moment about the fuselage longitudinal axis), has significant effect on the failure load of the lugs. Higher absolute values of Mx give lower failure loads. The predicted load, mode, and location of the failure of the 1985-certification test, 2003-subcomponent test, and the accident condition are in very good agreement. This agreement suggests that the 1985-certification and 2003- subcomponent tests represent the accident condition accurately. The failure mode of the right rear lug for the 1985-certification test, 2003-subcomponent test, and the accident load case is identified as a

  9. Derived Basic Ability Factors: A Factor Analysis Replication Study.

    ERIC Educational Resources Information Center

    Lee, Mickey, M.; Lee, Lynda Newby

    The purpose of this study was to replicate the study conducted by Potter, Sagraves, and McDonald to determine whether their recommended analysis could separate criterion variables into similar factors that were stable from year to year and from school to school. The replication samples consisted of all students attending Louisiana State University…

  10. Logistic regression analysis of risk factors for postoperative recurrence of spinal tumors and analysis of prognostic factors.

    PubMed

    Zhang, Shanyong; Yang, Lili; Peng, Chuangang; Wu, Minfei

    2018-02-01

    The aim of the present study was to investigate the risk factors for postoperative recurrence of spinal tumors by logistic regression analysis and analysis of prognostic factors. In total, 77 male and 48 female patients with spinal tumor were selected in our hospital from January, 2010 to December, 2015 and divided into the benign (n=76) and malignant groups (n=49). All the patients underwent microsurgical resection of spinal tumors and were reviewed regularly 3 months after operation. The McCormick grading system was used to evaluate the postoperative spinal cord function. Data were subjected to statistical analysis. Of the 125 cases, 63 cases showed improvement after operation, 50 cases were stable, and deterioration was found in 12 cases. The improvement rate of patients with cervical spine tumor, which reached 56.3%, was the highest. Fifty-two cases of sensory disturbance, 34 cases of pain, 30 cases of inability to exercise, 26 cases of ataxia, and 12 cases of sphincter disorders were found after operation. Seventy-two cases (57.6%) underwent total resection, 18 cases (14.4%) received subtotal resection, 23 cases (18.4%) received partial resection, and 12 cases (9.6%) were only treated with biopsy/decompression. Postoperative recurrence was found in 57 cases (45.6%). The mean recurrence time of patients in the malignant group was 27.49±6.09 months, and the mean recurrence time of patients in the benign group was 40.62±4.34. The results were significantly different (P<0.001). Recurrence was found in 18 cases of the benign group and 39 cases of the malignant group, and results were significantly different (P<0.001). Tumor recurrence was shorter in patients with a higher McCormick grade (P<0.001). Recurrence was found in 13 patients with resection and all the patients with partial resection or biopsy/decompression. The results were significantly different (P<0.001). Logistic regression analysis of total resection-related factors showed that total resection

  11. Logistic regression analysis of risk factors for postoperative recurrence of spinal tumors and analysis of prognostic factors

    PubMed Central

    Zhang, Shanyong; Yang, Lili; Peng, Chuangang; Wu, Minfei

    2018-01-01

    The aim of the present study was to investigate the risk factors for postoperative recurrence of spinal tumors by logistic regression analysis and analysis of prognostic factors. In total, 77 male and 48 female patients with spinal tumor were selected in our hospital from January, 2010 to December, 2015 and divided into the benign (n=76) and malignant groups (n=49). All the patients underwent microsurgical resection of spinal tumors and were reviewed regularly 3 months after operation. The McCormick grading system was used to evaluate the postoperative spinal cord function. Data were subjected to statistical analysis. Of the 125 cases, 63 cases showed improvement after operation, 50 cases were stable, and deterioration was found in 12 cases. The improvement rate of patients with cervical spine tumor, which reached 56.3%, was the highest. Fifty-two cases of sensory disturbance, 34 cases of pain, 30 cases of inability to exercise, 26 cases of ataxia, and 12 cases of sphincter disorders were found after operation. Seventy-two cases (57.6%) underwent total resection, 18 cases (14.4%) received subtotal resection, 23 cases (18.4%) received partial resection, and 12 cases (9.6%) were only treated with biopsy/decompression. Postoperative recurrence was found in 57 cases (45.6%). The mean recurrence time of patients in the malignant group was 27.49±6.09 months, and the mean recurrence time of patients in the benign group was 40.62±4.34. The results were significantly different (P<0.001). Recurrence was found in 18 cases of the benign group and 39 cases of the malignant group, and results were significantly different (P<0.001). Tumor recurrence was shorter in patients with a higher McCormick grade (P<0.001). Recurrence was found in 13 patients with resection and all the patients with partial resection or biopsy/decompression. The results were significantly different (P<0.001). Logistic regression analysis of total resection-related factors showed that total resection

  12. Psychological first aid training after Japan's triple disaster: changes in perceived self competency.

    PubMed

    Semlitz, Linda; Ogiwara, Kaori; Weissbecker, Inka; Gilbert, Elizabeth; Sato, Maiko; Taniguchi, Machi; Ishii, Chikako; Sawa, Chie

    2013-01-01

    International Medical Corps and TELL, a local mental health non-profit organization in Japan, collaborated to develop localized Psychological First Aid (PFA) training of welfare and volunteer organizations supporting survivors of the Japan March 11, 2011 triple disaster The trainings significantly increased participants 'perceived competency in applying PFA principles and in interacting with the disaster affected populations in a safe manner The collaboration between International Medical Corps and TELL in developing, implementing and evaluating the training has potential to inform PFA activities in other disaster affected settings.

  13. The Effect of Scattering and Absorption on Noise from a Cavitating Noise Source in the Subsurface Ocean Layer.

    DTIC Science & Technology

    1981-06-01

    for a de- tection probability of PD and associated false alarm probability PFA (in dB). 21 - - - II V. REFERENCE MODEL A. INTRODUCTION In order to...space for which to choose HI . PFA = P (wI 0o)dw = Q(---) (26) j 0 Similarity, the miss probability=l-detection probability is obtained by integrating...31) = 2 (1+ (22 [()BT z] ~Z The input signal-to-noise ratio: S/N(input) - a2 (32) The probability of false alarm: PFA = Q[ tB(j-I) 1 (33) The

  14. Environmentally Adaptive UXO Detection and Classification Systems

    DTIC Science & Technology

    2016-04-01

    probability of false alarm ( Pfa ), as well as Receiver Op- erating Characteristic (ROC) curve and confusion matrix characteristics. The results of these...techniques at a false alarm probability of Pfa = 1× 10−3. X̃ = g(X). In this case, the problem remains invariant to the group of transformations G = { g : g(X...and observed target responses as well as the probability of detection versus SNR for both detection techniques at Pfa = 1× 10−3. with N = 128 and M = 50

  15. On the Likelihood Ratio Test for the Number of Factors in Exploratory Factor Analysis

    ERIC Educational Resources Information Center

    Hayashi, Kentaro; Bentler, Peter M.; Yuan, Ke-Hai

    2007-01-01

    In the exploratory factor analysis, when the number of factors exceeds the true number of factors, the likelihood ratio test statistic no longer follows the chi-square distribution due to a problem of rank deficiency and nonidentifiability of model parameters. As a result, decisions regarding the number of factors may be incorrect. Several…

  16. A Brief History of the Philosophical Foundations of Exploratory Factor Analysis.

    ERIC Educational Resources Information Center

    Mulaik, Stanley A.

    1987-01-01

    Exploratory factor analysis derives its key ideas from many sources, including Aristotle, Francis Bacon, Descartes, Pearson and Yule, and Kant. The conclusions of exploratory factor analysis are never complete without subsequent confirmatory factor analysis. (Author/GDC)

  17. Hand function evaluation: a factor analysis study.

    PubMed

    Jarus, T; Poremba, R

    1993-05-01

    The purpose of this study was to investigate hand function evaluations. Factor analysis with varimax rotation was used to assess the fundamental characteristics of the items included in the Jebsen Hand Function Test and the Smith Hand Function Evaluation. The study sample consisted of 144 subjects without disabilities and 22 subjects with Colles fracture. Results suggest a four factor solution: Factor I--pinch movement; Factor II--grasp; Factor III--target accuracy; and Factor IV--activities of daily living. These categories differentiated the subjects without Colles fracture from the subjects with Colles fracture. A hand function evaluation consisting of these four factors would be useful. Such an evaluation that can be used for current clinical purposes is provided.

  18. Structural and surface functionality changes in reticulated vitreous carbon produced from poly(furfuryl alcohol) with sodium hydroxide additions

    NASA Astrophysics Data System (ADS)

    Oishi, Silvia Sizuka; Botelho, Edson Cocchieri; Rezende, Mirabel Cerqueira; Ferreira, Neidenêi Gomes

    2017-02-01

    The use of sodium hydroxide to neutralize the acid catalyst increases the storage life of poly(furfuryl alcohol) (PFA) resin avoiding its continuous polymerization. In this work, a concentrated sodium hydroxide solution (NaOH) was added directly to the PFA resin in order to minimize the production of wastes generated when PFA is washed with diluted basic solution. Thus, different amounts of this concentrated basic solution were added to the resin up to reaching pH values of around 3, 5, 7, and 9. From these four types of modified PFA two sample sets of reticulated vitreous carbon (RVC) were processed and heat treated at two different temperatures (1000 and 1700 °C). A correlation among cross-link density of PFA and RVC morphology, structural ordering and surface functionalities was systematically studied using Fourier transform infrared spectroscopy, scanning electron microscopy, Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy techniques. The PFA neutralization (pH 7) led to its higher polymerization degree, promoting a crystallinity decrease on RVC treated at 1000 °C as well as its highest percentages of carboxylic groups on surface. A NaOH excess (pH 9) substantially increased the RVC oxygen content, but its crystallinity remained similar to those for samples from pH 3 and 5 treated at 1000 °C, probably due to the reduced presence of carboxylic group and the lower polymerization degree of its cured resin. Samples with pH 3 and 5 heat treated at 1000 and 1700 °C can be considered the most ordered which indicated that small quantities of NaOH may be advantageous to minimize continuous polymerization of PFA resin increasing its storage life and improving RVC microstructure.

  19. Strength, leachability and microstructure characteristics of cement-based solidified plating sludge

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

    Asavapisit, Suwimol; Naksrichum, Siripat; Harnwajanawong, Naraporn

    2005-06-01

    The solidification of the stabilized zinc-cyanide plating sludge was carried out using ordinary Portland cement (OPC) and pulverized fuel ash (PFA) as solidification binders. The plating sludge were used at the level of 0%, 10%, 20% and 30% dry weight, and PFA was used to replace OPC at 0%, 10%, 20% and 30% dry weight, respectively. Experimental results showed that a significant reduction in strength was observed when the plating sludge was added to both the OPC and OPC/PFA binders, but the negative effect was minimized when PFA was used as part substitute for OPC. SEM observation reveals that themore » deposition of the plating sludge on the surface of the clinkers and PFA could be the cause for hydration retardation. In addition, calcium zinc hydroxide hydrate complex and the unreacted di- and tricalcium silicates were the major phases in X-ray diffraction (XRD) patterns of the solidified plating waste hydrated for 28 days, although the retardation effect on hydration reactions but Cr concentration in toxicity characteristic leaching procedure (TCLP) leachates was lower than the U.S. EPA regulatory limit.« less

  20. Portable Fan Assembly for the International Space Station

    NASA Technical Reports Server (NTRS)

    Jenkins, Arthur A.; Roman, Monsi C.

    1999-01-01

    NASA/ Marshall Space Flight Center (NASA/MSFC) is responsible for the design and fabrication of a Portable Fan Assembly (PFA) for the International Space Station (ISS). The PFA will be used to enhance ventilation inside the ISS modules as needed for crew comfort and for rack rotation. The PFA consists of the fan on-orbit replaceable unit (ORU) and two noise suppression packages (silencers). The fan ORU will have a mechanical interface with the Seat Track Equipment Anchor Assembly, in addition to the power supply module which includes a DC-DC converter, on/standby switch, speed control, power cable and connector. This paper provides a brief development history, including the criteria used for the fan, and a detailed description of the PFA operational configurations. Space Station requirements as well as fan performance characteristics are also discussed.

  1. Multivariate analysis of prognostic factors in synovial sarcoma.

    PubMed

    Koh, Kyoung Hwan; Cho, Eun Yoon; Kim, Dong Wook; Seo, Sung Wook

    2009-11-01

    Many studies have described the diversity of synovial sarcoma in terms of its biological characteristics and clinical features. Moreover, much effort has been expended on the identification of prognostic factors because of unpredictable behaviors of synovial sarcomas. However, with the exception of tumor size, published results have been inconsistent. We attempted to identify independent risk factors using survival analysis. Forty-one consecutive patients with synovial sarcoma were prospectively followed from January 1997 to March 2008. Overall and progression-free survival for age, sex, tumor size, tumor location, metastasis at presentation, histologic subtype, chemotherapy, radiation therapy, and resection margin were analyzed, and standard multivariate Cox proportional hazard regression analysis was used to evaluate potential prognostic factors. Tumor size (>5 cm), nonlimb-based tumors, metastasis at presentation, and a monophasic subtype were associated with poorer overall survival. Multivariate analysis showed metastasis at presentation and monophasic tumor subtype affected overall survival. For the progression-free survival, monophasic subtype was found to be only 1 prognostic factor. The study confirmed that histologic subtype is the single most important independent prognostic factors of synovial sarcoma regardless of tumor stage.

  2. Target and Clutter Scattering and their Effects on Military Radar Performance: Electromagnetic Wave Propagation Panel Specialists Meeting Held in Ottawa, Canada on 6-9 May 1991 (Diffraction par les Cibles et le Fouillis et ses Effets sur les Performances des Radars Militaires)

    DTIC Science & Technology

    1991-09-01

    In subsequent discussions, we shall classify a clutter process to be 2-7 predominantly Rayleigh if the value of f is less than 0.8, and the Pfa ...classified as "others’, the Pfa vs threshold curve , is closer to the Ricean model than to the Rayleigh model, and the value of the parameter 0 was usually...better, and for precipitation clutter the lattice was 4 to approximation of "...equally likely". PD and PFA are 6 dB bettor, here specified a 0.5 and 0.01

  3. Organization of the Topical Meeting on Optical Computing Held in Toulon, France on 29 August-2 September 1988

    DTIC Science & Technology

    1988-09-02

    ERIN POMMEL STP..1 6.520 ERLANGEN PFA Docteur BUFOGGRAF KPUPP ATLAS ELEKTR’JN K Grnbt SEEALDS2%JCr-EP 1IEEPSTPR. 235 "ademofiselie CENZ N5’T!TUIT F P...ANOE’?YA-,NDTE P"Hy’ 7EII HOCHS1CHIULcTPASSE 2 6100 DAPMSTAOT PTA Monsieur DLILTZ HEI DRUN SCHMlITZER UINIVERSITAT-P11Y3K 0-84 PEGENSBIJRG PFA ...LOIIMANN 1UNIYEDRSTAT, PHY1,SiV >1aderrioiele SCHITZER UVVERSITY OF REGE.JSSL,: ROMMEL STR. 8520 ERLANGEN PFA 84 REGENSBURG RFA Monsieur MARTINI DFYLR

  4. Factor Analysis for Clustered Observations.

    ERIC Educational Resources Information Center

    Longford, N. T.; Muthen, B. O.

    1992-01-01

    A two-level model for factor analysis is defined, and formulas for a scoring algorithm for this model are derived. A simple noniterative method based on decomposition of total sums of the squares and cross-products is discussed and illustrated with simulated data and data from the Second International Mathematics Study. (SLD)

  5. Using factor analysis to identify neuromuscular synergies during treadmill walking

    NASA Technical Reports Server (NTRS)

    Merkle, L. A.; Layne, C. S.; Bloomberg, J. J.; Zhang, J. J.

    1998-01-01

    Neuroscientists are often interested in grouping variables to facilitate understanding of a particular phenomenon. Factor analysis is a powerful statistical technique that groups variables into conceptually meaningful clusters, but remains underutilized by neuroscience researchers presumably due to its complicated concepts and procedures. This paper illustrates an application of factor analysis to identify coordinated patterns of whole-body muscle activation during treadmill walking. Ten male subjects walked on a treadmill (6.4 km/h) for 20 s during which surface electromyographic (EMG) activity was obtained from the left side sternocleidomastoid, neck extensors, erector spinae, and right side biceps femoris, rectus femoris, tibialis anterior, and medial gastrocnemius. Factor analysis revealed 65% of the variance of seven muscles sampled aligned with two orthogonal factors, labeled 'transition control' and 'loading'. These two factors describe coordinated patterns of muscular activity across body segments that would not be evident by evaluating individual muscle patterns. The results show that factor analysis can be effectively used to explore relationships among muscle patterns across all body segments to increase understanding of the complex coordination necessary for smooth and efficient locomotion. We encourage neuroscientists to consider using factor analysis to identify coordinated patterns of neuromuscular activation that would be obscured using more traditional EMG analyses.

  6. A Factor Analysis of the BSRI and the PAQ.

    ERIC Educational Resources Information Center

    Edwards, Teresa A.; And Others

    Factor analysis of the Bem Sex Role Inventory (BSRI) and the Personality Attributes Questionnaire (PAQ) was undertaken to study the independence of the masculine and feminine scales within each instrument. Both instruments were administered to undergraduate education majors. Analysis of primary first and second order factors of the BSRI indicated…

  7. Structural Analysis of the Right Rear Lug of American Airlines Flight 587

    NASA Technical Reports Server (NTRS)

    Raju, Ivatury S.; Glaessgen, Edward H.; Mason, Brian H.; Krishnamurthy, Thiagarajan; Davila, Carlos G.

    2006-01-01

    A detailed finite element analysis of the right rear lug of the American Airlines Flight 587 - Airbus A300-600R was performed as part of the National Transportation Safety Board s failure investigation of the accident that occurred on November 12, 2001. The loads experienced by the right rear lug are evaluated using global models of the vertical tail, local models near the right rear lug, and a global-local analysis procedure. The right rear lug was analyzed using two modeling approaches. In the first approach, solid-shell type modeling is used, and in the second approach, layered-shell type modeling is used. The solid-shell and the layered-shell modeling approaches were used in progressive failure analyses (PFA) to determine the load, mode, and location of failure in the right rear lug under loading representative of an Airbus certification test conducted in 1985 (the 1985-certification test). Both analyses were in excellent agreement with each other on the predicted failure loads, failure mode, and location of failure. The solid-shell type modeling was then used to analyze both a subcomponent test conducted by Airbus in 2003 (the 2003-subcomponent test) and the accident condition. Excellent agreement was observed between the analyses and the observed failures in both cases. The moment, Mx (moment about the fuselage longitudinal axis), has significant effect on the failure load of the lugs. Higher absolute values of Mx give lower failure loads. The predicted load, mode, and location of the failure of the 1985- certification test, 2003-subcomponent test, and the accident condition are in very good agreement. This agreement suggests that the 1985-certification and 2003-subcomponent tests represent the accident condition accurately. The failure mode of the right rear lug for the 1985-certification test, 2003-subcomponent test, and the accident load case is identified as a cleavage-type failure. For the accident case, the predicted failure load for the right rear lug

  8. Establishing Factor Validity Using Variable Reduction in Confirmatory Factor Analysis.

    ERIC Educational Resources Information Center

    Hofmann, Rich

    1995-01-01

    Using a 21-statement attitude-type instrument, an iterative procedure for improving confirmatory model fit is demonstrated within the context of the EQS program of P. M. Bentler and maximum likelihood factor analysis. Each iteration systematically eliminates the poorest fitting statement as identified by a variable fit index. (SLD)

  9. First responders and psychological first aid.

    PubMed

    Pekevski, Jordan

    2013-01-01

    Emergencies and disasters are common and occur on a daily basis. Although most survivors will not experience any long-term negative mental health effects, some will. First responders tend to have first contact with the survivors and, therefore, are in a position to provide needed mental health assistance to survivors. Psychological first aid (PFA) is an evidence-informed approach to providing support to survivors following a serious crisis event, and it aims to reduce the initial distress of the traumatic event and to promote adaptive functioning and coping. PFA has gained a great deal of attention lately, likely due to the fact that it is easy to provide. This article discusses the potential negative effects of emergencies and disasters on mental health, provides a description of PFA and discusses its application, and provides an overview of the research base of PFA and a discussion on the need for future research.

  10. Factors affecting job satisfaction in nurse faculty: a meta-analysis.

    PubMed

    Gormley, Denise K

    2003-04-01

    Evidence in the literature suggests job satisfaction can make a difference in keeping qualified workers on the job, but little research has been conducted focusing specifically on nursing faculty. Several studies have examined nurse faculty satisfaction in relationship to one or two influencing factors. These factors include professional autonomy, leader role expectations, organizational climate, perceived role conflict and role ambiguity, leadership behaviors, and organizational characteristics. This meta-analysis attempts to synthesize the various studies conducted on job satisfaction in nursing faculty and analyze which influencing factors have the greatest effect. The procedure used for this meta-analysis consisted of reviewing studies to identify factors influencing job satisfaction, research questions, sample size reported, instruments used for measurement of job satisfaction and influencing factors, and results of statistical analysis.

  11. The Recoverability of P-Technique Factor Analysis

    ERIC Educational Resources Information Center

    Molenaar, Peter C. M.; Nesselroade, John R.

    2009-01-01

    It seems that just when we are about to lay P-technique factor analysis finally to rest as obsolete because of newer, more sophisticated multivariate time-series models using latent variables--dynamic factor models--it rears its head to inform us that an obituary may be premature. We present the results of some simulations demonstrating that even…

  12. Bootstrap Confidence Intervals for Ordinary Least Squares Factor Loadings and Correlations in Exploratory Factor Analysis

    ERIC Educational Resources Information Center

    Zhang, Guangjian; Preacher, Kristopher J.; Luo, Shanhong

    2010-01-01

    This article is concerned with using the bootstrap to assign confidence intervals for rotated factor loadings and factor correlations in ordinary least squares exploratory factor analysis. Coverage performances of "SE"-based intervals, percentile intervals, bias-corrected percentile intervals, bias-corrected accelerated percentile…

  13. Donor retention in health care in Iran: a factor analysis

    PubMed Central

    Aghababa, Sara; Nasiripour, Amir Ashkan; Maleki, Mohammadreza; Gohari, Mahmoodreza

    2017-01-01

    Background: Long-term financial support is essential for the survival of a charitable organization. Health charities need to identify the effective factors influencing donor retention. Methods: In the present study, the items of a questionnaire were derived from both literature review and semi-structured interviews related to donor retention. Using a purposive sampling, 300 academic and executive practitioners were selected. After the follow- up, a total of 243 usable questionnaires were prepared for factor analysis. The questionnaire was validated based on the face and content validity and reliability through Cronbach’s α-coefficient. Results: The results of exploratory factor analysis extracted 2 factors for retention: donor factor (variance = 33.841%; Cronbach’s α-coefficient = 90.2) and charity factor (variance = 29.038%; Cronbach’s α-coefficient = 82.8), respectively. Subsequently, confirmatory factor analysis was applied to support the overall reasonable fit. Conclusions: In this study, it was found that repeated monetary donations are supplied to the charitable organizations when both aspects of donor factor (retention factor and charity factor) for retention are taken into consideration. This model could provide a perspective for making sustainable donations and charitable giving PMID:28955663

  14. The Factor Structure of the English Language Development Assessment: A Confirmatory Factor Analysis

    ERIC Educational Resources Information Center

    Kuriakose, Anju

    2011-01-01

    This study investigated the internal factor structure of the English language development Assessment (ELDA) using confirmatory factor analysis. ELDA is an English language proficiency test developed by a consortium of multiple states and is used to identify and reclassify English language learners in kindergarten to grade 12. Scores on item…

  15. Influential Observations in Principal Factor Analysis.

    ERIC Educational Resources Information Center

    Tanaka, Yutaka; Odaka, Yoshimasa

    1989-01-01

    A method is proposed for detecting influential observations in iterative principal factor analysis. Theoretical influence functions are derived for two components of the common variance decomposition. The major mathematical tool is the influence function derived by Tanaka (1988). (SLD)

  16. A hyper-thermostable α-amylase from Pyrococcus furiosus accumulates in Nicotiana tabacum as functional aggregates.

    PubMed

    Zhu, Hong; Reynolds, L Bruce; Menassa, Rima

    2017-06-19

    Alpha amylase hydrolyzes α-bonds of polysaccharides such as starch and produces malto-oligosaccharides. Its starch saccharification applications make it an essential enzyme in the textile, food and brewing industries. Commercially available α-amylase is mostly produced from Bacillus or Aspergillus. A hyper-thermostable and Ca 2++ independent α-amylase from Pyrococcus furiosus (PFA) expressed in E.coli forms insoluble inclusion bodies and thus is not feasible for industrial applications. We expressed PFA in Nicotiana tabacum and found that plant-produced PFA forms functional aggregates with an accumulation level up to 3.4 g/kg FW (fresh weight) in field conditions. The aggregates are functional without requiring refolding and therefore have potential to be applied as homogenized plant tissue without extraction or purification. PFA can also be extracted from plant tissue upon dissolution in a mild reducing buffer containing SDS. Like the enzyme produced in P. furiosus and in E. coli, plant produced PFA preserves hyper-thermophilicity and hyper-thermostability and has a long shelf life when stored in lyophilized leaf tissue. With tobacco's large biomass and high yield, hyper-thermostable α-amylase was produced at a scale of 42 kg per hectare. Tobacco may be a suitable bioreactor for industrial production of active hyperthermostable alpha amylase.

  17. Application of factor analysis to the water quality in reservoirs

    NASA Astrophysics Data System (ADS)

    Silva, Eliana Costa e.; Lopes, Isabel Cristina; Correia, Aldina; Gonçalves, A. Manuela

    2017-06-01

    In this work we present a Factor Analysis of chemical and environmental variables of the water column and hydro-morphological features of several Portuguese reservoirs. The objective is to reduce the initial number of variables, keeping their common characteristics. Using the Factor Analysis, the environmental variables measured in the epilimnion and in the hypolimnion, together with the hydromorphological characteristics of the dams were reduced from 63 variables to only 13 factors, which explained a total of 83.348% of the variance in the original data. After performing rotation using the Varimax method, the relations between the factors and the original variables got clearer and more explainable, which provided a Factor Analysis model for these environmental variables using 13 varifactors: Water quality and distance to the source, Hypolimnion chemical composition, Sulfite-reducing bacteria and nutrients, Coliforms and faecal streptococci, Reservoir depth, Temperature, Location, among other factors.

  18. Comparison of a portable micro-X-ray fluorescence spectrometry with inductively coupled plasma atomic emission spectrometry for the ancient ceramics analysis

    NASA Astrophysics Data System (ADS)

    Papadopoulou, D. N.; Zachariadis, G. A.; Anthemidis, A. N.; Tsirliganis, N. C.; Stratis, J. A.

    2004-12-01

    Two multielement instrumental methods of analysis, micro X-ray fluorescence spectrometry (micro-XRF) and inductively coupled plasma atomic emission spectrometry (ICP-AES) were applied for the analysis of 7th and 5th century B.C. ancient ceramic sherds in order to evaluate the above two methods and to assess the potential to use the current compact and portable micro-XRF instrument for the in situ analysis of ancient ceramics. The distinguishing factor of interest is that micro-XRF spectrometry offers the possibility of a nondestructive analysis, an aspect of primary importance in the compositional analysis of cultural objects. Micro-XRF measurements were performed firstly directly on the ceramic sherds with no special pretreatment apart from surface cleaning (micro-XRF on sherds) and secondly on pressed pellet disks which were prepared for each ceramic sherd (micro-XRF on pellet). For the ICP-AES determination of elements, test solutions were prepared by the application of a microwave-assisted decomposition procedure in closed high-pressure PFA vessels. Also, the standard reference material SARM 69 was used for the efficiency calibration of the micro-XRF instrument and was analysed by both methods. In order to verify the calibration, the standard reference materials NCS DC 73332 and SRM620 as well as the reference materials AWI-1 and PRI-1 were analysed by micro-XRF. Elemental concentrations determined by the three analytical procedures (ICP-AES, micro-XRF on sherds and micro-XRF on pellets) were statistically treated by correlation analysis and Student's t-test (at the 95% confidence level).

  19. Algal toxicity of the alternative disinfectants performic acid (PFA), peracetic acid (PAA), chlorine dioxide (ClO2) and their by-products hydrogen peroxide (H2O2) and chlorite (ClO2-).

    PubMed

    Chhetri, Ravi Kumar; Baun, Anders; Andersen, Henrik Rasmus

    2017-05-01

    Environmental effect evaluation of disinfection of combined sewer overflow events with alternative chemical disinfectants requires that the environmental toxicity of the disinfectants and the main by-products of their use are known. Many disinfectants degrade quickly in water which should be included in the evaluation of both their toxicity as determined in standardized tests and their possible negative effect in the water environment. Here we evaluated according to the standardized ISO 8692 test the toxicity towards the green microalgae, Pseudokirchneriella subcapitata, of three disinfectants: performic acid (PFA), peracetic acid (PAA) and chlorine dioxide (ClO 2 ) as well as two by-products of their use: hydrogen peroxide (H 2 O 2 ) and chlorite. All of the five chemicals investigated showed clear toxicity to the algae with well-defined dose response curves. The EC 50 values ranged from 0.16 to 2.9mg/L based on nominal concentrations leading to the labeling of the chemicals as either toxic or very toxic. The five investigated chemicals decreased in toxicity in the order chlorine dioxide, performic acid, peracetic acid, chlorite and hydrogen peroxide. The stability of the chemicals increased in the same order as the toxicity decrease. This indicates that even though ClO 2 has the highest environmental hazard potential, it may still be suitable as an alternative disinfectant due to its rapid degradation in water. Copyright © 2016 Elsevier GmbH. All rights reserved.

  20. Docosahexaenoic acid protects from dendritic pathology in an Alzheimer's disease mouse model.

    PubMed

    Calon, Frédéric; Lim, Giselle P; Yang, Fusheng; Morihara, Takashi; Teter, Bruce; Ubeda, Oliver; Rostaing, Phillippe; Triller, Antoine; Salem, Norman; Ashe, Karen H; Frautschy, Sally A; Cole, Greg M

    2004-09-02

    Learning and memory depend on dendritic spine actin assembly and docosahexaenoic acid (DHA), an essential n-3 (omega-3) polyunsaturated fatty acid (PFA). High DHA consumption is associated with reduced Alzheimer's disease (AD) risk, yet mechanisms and therapeutic potential remain elusive. Here, we report that reduction of dietary n-3 PFA in an AD mouse model resulted in 80%-90% losses of the p85alpha subunit of phosphatidylinositol 3-kinase and the postsynaptic actin-regulating protein drebrin, as in AD brain. The loss of postsynaptic proteins was associated with increased oxidation, without concomitant neuron or presynaptic protein loss. n-3 PFA depletion increased caspase-cleaved actin, which was localized in dendrites ultrastructurally. Treatment of n-3 PFA-restricted mice with DHA protected against these effects and behavioral deficits and increased antiapoptotic BAD phosphorylation. Since n-3 PFAs are essential for p85-mediated CNS insulin signaling and selective protection of postsynaptic proteins, these findings have implications for neurodegenerative diseases where synaptic loss is critical, especially AD.

  1. The Convergence of Heat, Groundwater & Fracture Permeability. Innovative Play Fairway Modelling Applied to the Tularosa Basin Phase 1 Project Report

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

    Bennett, Carlon R.; Nash, Gregory D.; Sorkhabi, Rasoul

    This report summarizes the activities and key findings of the project team occurring during Phase 1 (August 2014-October 2015) of the Tularosa Basin Geothermal Play Fairway Analysis Project. The Tularosa Basin Play Fairway Analysis (PFA) project tested two distinct geothermal exploration methodologies covering the entire basin within South Central New Mexico and Far West Texas. Throughout the initial phase of the project, the underexplored basin proved to be a challenging, yet ideal test bed to evaluate effectiveness of the team’s data collection techniques as well as the effectiveness of our innovative PFA. Phase 1 of the effort employed a low-cost,more » pragmatic approach using two methods to identify potential geothermal plays within the study area and then compared and contrasted the results of each method to rank and evaluate potential plays. Both methods appear to be very effective and highly transferable to other areas.« less

  2. A replication of a factor analysis of motivations for trapping

    USGS Publications Warehouse

    Schroeder, Susan; Fulton, David C.

    2015-01-01

    Using a 2013 sample of Minnesota trappers, we employed confirmatory factor analysis to replicate an exploratory factor analysis of trapping motivations conducted by Daigle, Muth, Zwick, and Glass (1998).  We employed the same 25 items used by Daigle et al. and tested the same five-factor structure using a recent sample of Minnesota trappers. We also compared motivations in our sample to those reported by Daigle et el.

  3. Genome analysis of Pseudoalteromonas flavipulchra JG1 reveals various survival advantages in marine environment.

    PubMed

    Yu, Min; Tang, Kaihao; Liu, Jiwen; Shi, Xiaochong; Gulder, Tobias A M; Zhang, Xiao-Hua

    2013-10-16

    Competition between bacteria for habitat and resources is very common in the natural environment and is considered to be a selective force for survival. Many strains of the genus Pseudoalteromonas were confirmed to produce bioactive compounds that provide those advantages over their competitors. In our previous study, P. flavipulchra JG1 was found to synthesize a Pseudoalteromonas flavipulchra antibacterial Protein (PfaP) with L-amino acid oxidase activity and five small chemical compounds, which were the main competitive agents of the strain. In addition, the genome of this bacterium has been previously sequenced as Whole Genome Shotgun project (PMID: 22740664). In this study, more extensive genomic analysis was performed to identify specific genes or gene clusters which related to its competitive feature, and further experiments were carried out to confirm the physiological roles of these genes when competing with other microorganisms in marine environment. The antibacterial protein PfaP may also participate in the biosynthesis of 6-bromoindolyl-3-acetic acid, indicating a synergistic effect between the antibacterial macromolecule and small molecules. Chitinases and quorum quenching enzymes present in P. flavipulchra, which coincide with great chitinase and acyl homoserine lactones degrading activities of strain JG1, suggest other potential mechanisms contribute to antibacterial/antifungal activities. Moreover, movability and rapid response mechanisms to phosphorus starvation and other stresses, such as antibiotic, oxidative and heavy metal stress, enable JG1 to adapt to deleterious, fluctuating and oligotrophic marine environments. The genome of P. flavipulchra JG1 exhibits significant genetic advantages against other microorganisms, encoding antimicrobial agents as well as abilities to adapt to various adverse environments. Genes involved in synthesis of various antimicrobial substances enriches the antagonistic mechanisms of P. flavipulchra JG1 and affords

  4. On the Relations among Regular, Equal Unique Variances, and Image Factor Analysis Models.

    ERIC Educational Resources Information Center

    Hayashi, Kentaro; Bentler, Peter M.

    2000-01-01

    Investigated the conditions under which the matrix of factor loadings from the factor analysis model with equal unique variances will give a good approximation to the matrix of factor loadings from the regular factor analysis model. Extends the results to the image factor analysis model. Discusses implications for practice. (SLD)

  5. Deliberations about the functional benefits and complications of partial foot amputation: do we pay heed to the purported benefits at the expense of minimizing complications?

    PubMed

    Dillon, Michael P; Fatone, Stefania

    2013-08-01

    While discussion about the benefits and complications of partial foot amputation (PFA) is not new, much of it has hinged on anecdotal evidence and led to the popular view that the risk of complications and secondary amputation is reasonable when weighed against the perceived benefits associated with maintaining the ankle joint and residual foot length, including more normal walking, reduced energy expenditure, and improved quality of life. The research evidence makes it difficult not to question whether these benefits are valid and worth striving to achieve. When you consider that persons who undergo PFA are typically in the later years of their life and have limited mobility, it raises the question of whether we place too much emphasis on achieving the purported functional benefits of PFA and too little emphasis on achieving primary wound healing and mitigating the high rates of complications and subsequent amputation. If further research supports what we see emerging in the evidence, there will be a case to be made for selecting the level of PFA based primarily on the potential for wound healing, rather than trying to strike a balance with the perceived functional benefits. This may mean that transtibial amputation is preferable in many cases, given the lower rates of complications and secondary amputation, very similar function in terms of walking and energy expenditure, and similar lived experience of limb loss when compared with persons with PFA. Further research is needed to better understand the complications and benefits of PFA to make this a more viable, first-and-final amputation procedure. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  6. Widespread occurrence of secondary lipid biosynthesis potential in microbial lineages.

    PubMed

    Shulse, Christine N; Allen, Eric E

    2011-01-01

    Bacterial production of long-chain omega-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3), is constrained to a narrow subset of marine γ-proteobacteria. The genes responsible for de novo bacterial PUFA biosynthesis, designated pfaEABCD, encode large, multi-domain protein complexes akin to type I iterative fatty acid and polyketide synthases, herein referred to as "Pfa synthases". In addition to the archetypal Pfa synthase gene products from marine bacteria, we have identified homologous type I FAS/PKS gene clusters in diverse microbial lineages spanning 45 genera representing 10 phyla, presumed to be involved in long-chain fatty acid biosynthesis. In total, 20 distinct types of gene clusters were identified. Collectively, we propose the designation of "secondary lipids" to describe these biosynthetic pathways and products, a proposition consistent with the "secondary metabolite" vernacular. Phylogenomic analysis reveals a high degree of functional conservation within distinct biosynthetic pathways. Incongruence between secondary lipid synthase functional clades and taxonomic group membership combined with the lack of orthologous gene clusters in closely related strains suggests horizontal gene transfer has contributed to the dissemination of specialized lipid biosynthetic activities across disparate microbial lineages.

  7. Factor Analysis of the Brazilian Version of UPPS Impulsive Behavior Scale

    PubMed Central

    Sediyama, Cristina Y. N.; Moura, Ricardo; Garcia, Marina S.; da Silva, Antonio G.; Soraggi, Carolina; Neves, Fernando S.; Albuquerque, Maicon R.; Whiteside, Setephen P.; Malloy-Diniz, Leandro F.

    2017-01-01

    Objective: To examine the internal consistency and factor structure of the Brazilian adaptation of the UPPS Impulsive Behavior Scale. Methods: UPPS is a self-report scale composed by 40 items assessing four factors of impulsivity: (a) urgency, (b) lack of premeditation; (c) lack of perseverance; (d) sensation seeking. In the present study 384 participants (278 women and 106 men), who were recruited from schools, universities, leisure centers and workplaces fulfilled the UPPS scale. An exploratory factor analysis was performed by using Varimax factor rotation and Kaiser Normalization, and we also conducted two confirmatory analyses to test the independency of the UPPS components found in previous analysis. Results: Results showed a decrease in mean UPPS total scores with age and this analysis showed that the youngest participants (below 30 years) scored significantly higher than the other groups over 30 years. No difference in gender was found. Cronbach’s alpha, results indicated satisfactory values for all subscales, with similar high values for the subscales and confirmatory factor analysis indexes also indicated a poor model fit. The results of two exploratory factor analysis were satisfactory. Conclusion: Our results showed that the Portuguese version has the same four-factor structure of the original and previous translations of the UPPS. PMID:28484414

  8. Factor Analysis of the Brazilian Version of UPPS Impulsive Behavior Scale.

    PubMed

    Sediyama, Cristina Y N; Moura, Ricardo; Garcia, Marina S; da Silva, Antonio G; Soraggi, Carolina; Neves, Fernando S; Albuquerque, Maicon R; Whiteside, Setephen P; Malloy-Diniz, Leandro F

    2017-01-01

    Objective: To examine the internal consistency and factor structure of the Brazilian adaptation of the UPPS Impulsive Behavior Scale. Methods: UPPS is a self-report scale composed by 40 items assessing four factors of impulsivity: (a) urgency, (b) lack of premeditation; (c) lack of perseverance; (d) sensation seeking. In the present study 384 participants (278 women and 106 men), who were recruited from schools, universities, leisure centers and workplaces fulfilled the UPPS scale. An exploratory factor analysis was performed by using Varimax factor rotation and Kaiser Normalization, and we also conducted two confirmatory analyses to test the independency of the UPPS components found in previous analysis. Results: Results showed a decrease in mean UPPS total scores with age and this analysis showed that the youngest participants (below 30 years) scored significantly higher than the other groups over 30 years. No difference in gender was found. Cronbach's alpha, results indicated satisfactory values for all subscales, with similar high values for the subscales and confirmatory factor analysis indexes also indicated a poor model fit. The results of two exploratory factor analysis were satisfactory. Conclusion: Our results showed that the Portuguese version has the same four-factor structure of the original and previous translations of the UPPS.

  9. Quantitative analysis of in situ optical diagnostics for inferring particle/aggregate parameters in flames: Implications for soot surface growth and total emissivity

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

    Koeylue, U.O.

    1997-05-01

    An in situ particulate diagnostic/analysis technique is outlined based on the Rayleigh-Debye-Gans polydisperse fractal aggregate (RDG/PFA) scattering interpretation of absolute angular light scattering and extinction measurements. Using proper particle refractive index, the proposed data analysis method can quantitatively yield all aggregate parameters (particle volume fraction, f{sub v}, fractal dimension, D{sub f}, primary particle diameter, d{sub p}, particle number density, n{sub p}, and aggregate size distribution, pdf(N)) without any prior knowledge about the particle-laden environment. The present optical diagnostic/interpretation technique was applied to two different soot-containing laminar and turbulent ethylene/air nonpremixed flames in order to assess its reliability. The aggregate interpretationmore » of optical measurements yielded D{sub f}, d{sub p}, and pdf(N) that are in excellent agreement with ex situ thermophoretic sampling/transmission electron microscope (TS/TEM) observations within experimental uncertainties. However, volume-equivalent single particle models (Rayleigh/Mie) overestimated d{sub p} by about a factor of 3, causing an order of magnitude underestimation in n{sub p}. Consequently, soot surface areas and growth rates were in error by a factor of 3, emphasizing that aggregation effects need to be taken into account when using optical diagnostics for a reliable understanding of soot formation/evolution mechanism in flames. The results also indicated that total soot emissivities were generally underestimated using Rayleigh analysis (up to 50%), mainly due to the uncertainties in soot refractive indices at infrared wavelengths. This suggests that aggregate considerations may not be essential for reasonable radiation heat transfer predictions from luminous flames because of fortuitous error cancellation, resulting in typically a 10 to 30% net effect.« less

  10. A Factor Analysis of Learning Data and Selected Ability Test Scores

    ERIC Educational Resources Information Center

    Jones, Dorothy L.

    1976-01-01

    A verbal concept-learning task permitting the externalizing and quantifying of learning behavior and 16 ability tests were administered to female graduate students. Data were analyzed by alpha factor analysis and incomplete image analysis. Six alpha factors and 12 image factors were extracted and orthogonally rotated. Four areas of cognitive…

  11. Biological risk factors for suicidal behaviors: a meta-analysis

    PubMed Central

    Chang, B P; Franklin, J C; Ribeiro, J D; Fox, K R; Bentley, K H; Kleiman, E M; Nock, M K

    2016-01-01

    Prior studies have proposed a wide range of potential biological risk factors for future suicidal behaviors. Although strong evidence exists for biological correlates of suicidal behaviors, it remains unclear if these correlates are also risk factors for suicidal behaviors. We performed a meta-analysis to integrate the existing literature on biological risk factors for suicidal behaviors and to determine their statistical significance. We conducted a systematic search of PubMed, PsycInfo and Google Scholar for studies that used a biological factor to predict either suicide attempt or death by suicide. Inclusion criteria included studies with at least one longitudinal analysis using a biological factor to predict either of these outcomes in any population through 2015. From an initial screen of 2541 studies we identified 94 cases. Random effects models were used for both meta-analyses and meta-regression. The combined effect of biological factors produced statistically significant but relatively weak prediction of suicide attempts (weighted mean odds ratio (wOR)=1.41; CI: 1.09–1.81) and suicide death (wOR=1.28; CI: 1.13–1.45). After accounting for publication bias, prediction was nonsignificant for both suicide attempts and suicide death. Only two factors remained significant after accounting for publication bias—cytokines (wOR=2.87; CI: 1.40–5.93) and low levels of fish oil nutrients (wOR=1.09; CI: 1.01–1.19). Our meta-analysis revealed that currently known biological factors are weak predictors of future suicidal behaviors. This conclusion should be interpreted within the context of the limitations of the existing literature, including long follow-up intervals and a lack of tests of interactions with other risk factors. Future studies addressing these limitations may more effectively test for potential biological risk factors. PMID:27622931

  12. A Preliminary Evaluation of the Paid Feeding Assistant Regulation: Impact on Feeding Assistance Care Process Quality in Nursing Homes

    ERIC Educational Resources Information Center

    Simmons, Sandra F.; Bertrand, Rosanna; Shier, Victoria; Sweetland, Rebecca; Moore, Therese J.; Hurd, Donna T.; Schnelle, John F.

    2007-01-01

    Purpose: The Centers for Medicare and Medicaid Services and the Agency for Healthcare Research and Quality sponsored a nationwide study to evaluate the federal paid feeding assistant (PFA) regulation that allows nursing homes to hire single-task workers to provide feeding assistance to nursing home residents. Organizers designed the PFA regulation…

  13. A Longitudinal View of Educational Outcomes for "Preschool for All" Participants in Redwood City School District. Issue Brief

    ERIC Educational Resources Information Center

    Sanchez, Monika

    2014-01-01

    This report is a longitudinal examination of "Preschool for All" (PFA) participants, tracking students' experiences across their first four years in elementary school. It builds upon a 2009 study that found that PFA graduates in San Mateo County were better prepared for kindergarten than their classmates who had not attended preschool…

  14. Hierarchical Factoring Based On Image Analysis And Orthoblique Rotations.

    PubMed

    Stankov, L

    1979-07-01

    The procedure for hierarchical factoring suggested by Schmid and Leiman (1957) is applied within the framework of image analysis and orthoblique rotational procedures. It is shown that this approach necessarily leads to correlated higher order factors. Also, one can obtain a smaller number of factors than produced by typical hierarchical procedures.

  15. Human Factors Vehicle Displacement Analysis: Engineering In Motion

    NASA Technical Reports Server (NTRS)

    Atencio, Laura Ashley; Reynolds, David; Robertson, Clay

    2010-01-01

    While positioned on the launch pad at the Kennedy Space Center, tall stacked launch vehicles are exposed to the natural environment. Varying directional winds and vortex shedding causes the vehicle to sway in an oscillating motion. The Human Factors team recognizes that vehicle sway may hinder ground crew operation, impact the ground system designs, and ultimately affect launch availability . The objective of this study is to physically simulate predicted oscillation envelopes identified by analysis. and conduct a Human Factors Analysis to assess the ability to carry out essential Upper Stage (US) ground operator tasks based on predicted vehicle motion.

  16. Degradation behavior of carbon nanotubes/phenol-furfuryl alcohol multifunctional composites with aerospace application

    NASA Astrophysics Data System (ADS)

    Conejo, L. S.; Costa, M. L.; Oishi, S. S.; Botelho, E. C.

    2017-10-01

    Lightweight and highly conductive composite associated with good impact and tribological properties could be used in the aerospace industry to replace metal for an aircraft skin and still provide effective shielding against electromagnetic interference (EMI). Also, phenol-furfuryl alcohol resins (PFA) are excellent candidates to replace existing thermoset matrices used for obtaining glassy carbon, both in its pure form and reinforced with nanoscale structures. The synthesis of PFA allow obtaining a resin with better properties than that showed by conventional phenolic resins and with synthesis and cure processes more controlled than observed for the furfuryl alcohol resin. This work has as main purpose the synthesis and thermal characterization of PFA resin and its nanostructured composites with different concentrations of carbon nanotubes (0, 0.1, 0.5 and 1.0 wt%). PFA resin was synthesized with 1:2:1 molar ratio of phenol/formaldehyde/furfuryl alcohol, according to the more appropriate condition obtained previously. The specimens were evaluated by thermogravimetry (TGA) to knowledge of the temperature of thermal degradation, either by actual analyses as simulated by simulation heating rate conversion software (known as Highway Simulation). The introduction of CNT in PFA sample does not affect its thermal stability. The values of residual weight found for samples with CNT additions are close to the values of the phenolic resin in the literature (about 60% residual weight).

  17. Bayesian Factor Analysis When Only a Sample Covariance Matrix Is Available

    ERIC Educational Resources Information Center

    Hayashi, Kentaro; Arav, Marina

    2006-01-01

    In traditional factor analysis, the variance-covariance matrix or the correlation matrix has often been a form of inputting data. In contrast, in Bayesian factor analysis, the entire data set is typically required to compute the posterior estimates, such as Bayes factor loadings and Bayes unique variances. We propose a simple method for computing…

  18. Evaluation of Parallel Analysis Methods for Determining the Number of Factors

    ERIC Educational Resources Information Center

    Crawford, Aaron V.; Green, Samuel B.; Levy, Roy; Lo, Wen-Juo; Scott, Lietta; Svetina, Dubravka; Thompson, Marilyn S.

    2010-01-01

    Population and sample simulation approaches were used to compare the performance of parallel analysis using principal component analysis (PA-PCA) and parallel analysis using principal axis factoring (PA-PAF) to identify the number of underlying factors. Additionally, the accuracies of the mean eigenvalue and the 95th percentile eigenvalue criteria…

  19. Application of Factor Analysis on the Financial Ratios of Indian Cement Industry and Validation of the Results by Cluster Analysis

    NASA Astrophysics Data System (ADS)

    De, Anupam; Bandyopadhyay, Gautam; Chakraborty, B. N.

    2010-10-01

    Financial ratio analysis is an important and commonly used tool in analyzing financial health of a firm. Quite a large number of financial ratios, which can be categorized in different groups, are used for this analysis. However, to reduce number of ratios to be used for financial analysis and regrouping them into different groups on basis of empirical evidence, Factor Analysis technique is being used successfully by different researches during the last three decades. In this study Factor Analysis has been applied over audited financial data of Indian cement companies for a period of 10 years. The sample companies are listed on the Stock Exchange India (BSE and NSE). Factor Analysis, conducted over 44 variables (financial ratios) grouped in 7 categories, resulted in 11 underlying categories (factors). Each factor is named in an appropriate manner considering the factor loads and constituent variables (ratios). Representative ratios are identified for each such factor. To validate the results of Factor Analysis and to reach final conclusion regarding the representative ratios, Cluster Analysis had been performed.

  20. Deep Learning with Hierarchical Convolutional Factor Analysis

    PubMed Central

    Chen, Bo; Polatkan, Gungor; Sapiro, Guillermo; Blei, David; Dunson, David; Carin, Lawrence

    2013-01-01

    Unsupervised multi-layered (“deep”) models are considered for general data, with a particular focus on imagery. The model is represented using a hierarchical convolutional factor-analysis construction, with sparse factor loadings and scores. The computation of layer-dependent model parameters is implemented within a Bayesian setting, employing a Gibbs sampler and variational Bayesian (VB) analysis, that explicitly exploit the convolutional nature of the expansion. In order to address large-scale and streaming data, an online version of VB is also developed. The number of basis functions or dictionary elements at each layer is inferred from the data, based on a beta-Bernoulli implementation of the Indian buffet process. Example results are presented for several image-processing applications, with comparisons to related models in the literature. PMID:23787342

  1. Factor Analysis by Generalized Least Squares.

    ERIC Educational Resources Information Center

    Joreskog, Karl G.; Goldberger, Arthur S.

    Aitkin's generalized least squares (GLS) principle, with the inverse of the observed variance-covariance matrix as a weight matrix, is applied to estimate the factor analysis model in the exploratory (unrestricted) case. It is shown that the GLS estimates are scale free and asymptotically efficient. The estimates are computed by a rapidly…

  2. How to Compare Parametric and Nonparametric Person-Fit Statistics Using Real Data

    ERIC Educational Resources Information Center

    Sinharay, Sandip

    2017-01-01

    Person-fit assessment (PFA) is concerned with uncovering atypical test performance as reflected in the pattern of scores on individual items on a test. Existing person-fit statistics (PFSs) include both parametric and nonparametric statistics. Comparison of PFSs has been a popular research topic in PFA, but almost all comparisons have employed…

  3. Exploratory Factor Analysis of a Force Concept Inventory Data Set

    ERIC Educational Resources Information Center

    Scott, Terry F.; Schumayer, Daniel; Gray, Andrew R.

    2012-01-01

    We perform a factor analysis on a "Force Concept Inventory" (FCI) data set collected from 2109 respondents. We address two questions: the appearance of conceptual coherence in student responses to the FCI and some consequences of this factor analysis on the teaching of Newtonian mechanics. We will highlight the apparent conflation of Newton's…

  4. [Factor Analysis: Principles to Evaluate Measurement Tools for Mental Health].

    PubMed

    Campo-Arias, Adalberto; Herazo, Edwin; Oviedo, Heidi Celina

    2012-09-01

    The validation of a measurement tool in mental health is a complex process that usually starts by estimating reliability, to later approach its validity. Factor analysis is a way to know the number of dimensions, domains or factors of a measuring tool, generally related to the construct validity of the scale. The analysis could be exploratory or confirmatory, and helps in the selection of the items with better performance. For an acceptable factor analysis, it is necessary to follow some steps and recommendations, conduct some statistical tests, and rely on a proper sample of participants. Copyright © 2012 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  5. Analysis of Factors Influencing Creative Personality of Elementary School Students

    ERIC Educational Resources Information Center

    Park, Jongman; Kim, Minkee; Jang, Shinho

    2017-01-01

    This quantitative research examined factors that affect elementary students' creativity and how those factors correlate. Aiming to identify significant factors that affect creativity and to clarify the relationship between these factors by path analysis, this research was designed to be a stepping stone for creativity enhancement studies. Data…

  6. Generalized five-dimensional dynamic and spectral factor analysis

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

    El Fakhri, Georges; Sitek, Arkadiusz; Zimmerman, Robert E.

    2006-04-15

    We have generalized the spectral factor analysis and the factor analysis of dynamic sequences (FADS) in SPECT imaging to a five-dimensional general factor analysis model (5D-GFA), where the five dimensions are the three spatial dimensions, photon energy, and time. The generalized model yields a significant advantage in terms of the ratio of the number of equations to that of unknowns in the factor analysis problem in dynamic SPECT studies. We solved the 5D model using a least-squares approach. In addition to the traditional non-negativity constraints, we constrained the solution using a priori knowledge of both time and energy, assuming thatmore » primary factors (spectra) are Gaussian-shaped with full-width at half-maximum equal to gamma camera energy resolution. 5D-GFA was validated in a simultaneous pre-/post-synaptic dual isotope dynamic phantom study where {sup 99m}Tc and {sup 123}I activities were used to model early Parkinson disease studies. 5D-GFA was also applied to simultaneous perfusion/dopamine transporter (DAT) dynamic SPECT in rhesus monkeys. In the striatal phantom, 5D-GFA yielded significantly more accurate and precise estimates of both primary {sup 99m}Tc (bias=6.4%{+-}4.3%) and {sup 123}I (-1.7%{+-}6.9%) time activity curves (TAC) compared to conventional FADS (biases=15.5%{+-}10.6% in {sup 99m}Tc and 8.3%{+-}12.7% in {sup 123}I, p<0.05). Our technique was also validated in two primate dynamic dual isotope perfusion/DAT transporter studies. Biases of {sup 99m}Tc-HMPAO and {sup 123}I-DAT activity estimates with respect to estimates obtained in the presence of only one radionuclide (sequential imaging) were significantly lower with 5D-GFA (9.4%{+-}4.3% for {sup 99m}Tc-HMPAO and 8.7%{+-}4.1% for {sup 123}I-DAT) compared to biases greater than 15% for volumes of interest (VOI) over the reconstructed volumes (p<0.05). 5D-GFA is a novel and promising approach in dynamic SPECT imaging that can also be used in other modalities. It allows accurate and

  7. 49 CFR Appendix D to Part 172 - Rail Risk Analysis Factors

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Rail Risk Analysis Factors D Appendix D to Part... REQUIREMENTS, AND SECURITY PLANS Pt. 172, App. D Appendix D to Part 172—Rail Risk Analysis Factors A. This... safety and security risk analyses required by § 172.820. The risk analysis to be performed may be...

  8. 49 CFR Appendix D to Part 172 - Rail Risk Analysis Factors

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Rail Risk Analysis Factors D Appendix D to Part... REQUIREMENTS, AND SECURITY PLANS Pt. 172, App. D Appendix D to Part 172—Rail Risk Analysis Factors A. This... safety and security risk analyses required by § 172.820. The risk analysis to be performed may be...

  9. Self-assembly and reactive molding techniques for controlling the interface and dispersion of the particulate phase in nanocomposites

    NASA Astrophysics Data System (ADS)

    Pranger, Lawrence A.

    This research explored the processing and properties of PNCs using a polyfurfural alcohol (PFA) matrix. The precursor for PFA, furfuryl alcohol (FA) is sourced from feedstocks rich in hemicellulose, such as corn cobs, oat hulls and wood. To exploit FA as a polymerizable solvent, cellulose whiskers (CW) and montmorillonite clay (MMT) were used as the nanoparticle phase. Results from PNC processing show that CW and MMT can be dispersed in the PFA matrix by means of insitu polymerization, without the use of surfactants or dilution in solvents. Both CW and MMT nanoparticles catalyze the polymerization of furfuryl alcohol (FA). Moreover, the insitu intercalative polymerization of FA in the interlayer galleries of MMT leads to the complete exfoliation of the MMT in the PFA matrix. CW and MMT both function as effective matrix modifiers, increasing the thermal stability of PFA nanocomposites compared to pure PFA polymer. The increased thermal stability is seen as significant increases in the onset of degradation and in residual weight at high temperature. This research also explored the surface functionalization of Cu, Ni and Pt substrates by self-assembly of a range of difunctional linker molecules. Characterization by XPS and PM-IRRAS indicate that diisocyanides and dicarboxylic acids both form chemically "sticky" surfaces after self-assembly on Cu and Ni. Sticky surfaces may provide a means of increasing nanoparticle dispersion in metal nanocluster filled PNCs, by increasing their interaction with the matrix polymer. Another potential application for sticky surfaces on Cu is in the ongoing miniaturization of circuit boards. The functionalization of Cu bond pad substrates with linker molecules may provide an alternate means of bonding components to their bond pads, with higher placement accuracy compared to solder bumps.

  10. Outcomes of Patellofemoral Arthroplasty Based on Radiographic Severity.

    PubMed

    deDeugd, Casey M; Pareek, Ayoosh; Krych, Aaron J; Cummings, Nancy M; Dahm, Diane L

    2017-04-01

    Patellofemoral arthroplasty (PFA) is increasingly performed for symptomatic patellofemoral arthritis. The purpose of this study was to evaluate the outcomes of PFA based on preoperative radiographic severity of patellofemoral arthritis. All patients who underwent PFA for isolated patellofemoral arthritis between 2002 and 2013 and had undergone preoperative magnetic resonance imaging were identified. Radiographic severity of patellofemoral arthritis was classified according to the Iwano classification system. Groups were divided between mild (grade 0-I) and moderate to severe (grade II-IV) patellofemoral arthritis. Clinical outcomes were evaluated using the Knee Society scores (KSS), University of California at Los Angeles (UCLA) and Tegner scores. Seventy-five knees in 55 patients met inclusion criteria. Mean age was 51 years (range, 36 to 81), and mean follow-up was 3 years (range, 2 to 10). All patients had grade IV patellofemoral chondromalacia and/or significant subchondral cyst formation and edema on magnetic resonance imaging. On plain radiographs, there were no patients with Iwano grade 0, 21 grade I, 15 grade II, 21 grade III, and 18 grade IV patellofemoral arthritis. There was significantly more improvement in KSS pain (P = .046), KSS function (P = .02), University of California at Los Angeles (UCLA) (P = .046) and Tegner (P = .008) scores in the Iwano grade II-IV group vs the Iwano grade I group. Patient-reported pain quality improved significantly more following PFA in the grade II-IV group (P = .04). Patients with evidence of mild patellofemoral arthritis on plain radiographs demonstrated less improvement in pain and function after PFA than those with more advanced patellofemoral arthritis. Caution should be used when considering PFA for patients with minimal radiographic evidence of patellofemoral arthritis. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Examining evolving performance on the Force Concept Inventory using factor analysis

    NASA Astrophysics Data System (ADS)

    Semak, M. R.; Dietz, R. D.; Pearson, R. H.; Willis, C. W.

    2017-06-01

    The application of factor analysis to the Force Concept Inventory (FCI) has proven to be problematic. Some studies have suggested that factor analysis of test results serves as a helpful tool in assessing the recognition of Newtonian concepts by students. Other work has produced at best ambiguous results. For the FCI administered as a pre- and post-test, we see factor analysis as a tool by which the changes in conceptual associations made by our students may be gauged given the evolution of their response patterns. This analysis allows us to identify and track conceptual linkages, affording us insight as to how our students have matured due to instruction. We report on our analysis of 427 pre- and post-tests. The factor models for the pre- and post-tests are explored and compared along with the methodology by which these models were fit to the data. The post-test factor pattern is more aligned with an expert's interpretation of the questions' content, as it allows for a more readily identifiable relationship between factors and physical concepts. We discuss this evolution in the context of approaching the characteristics of an expert with force concepts. Also, we find that certain test items do not significantly contribute to the pre- or post-test factor models and attempt explanations as to why this is so. This may suggest that such questions may not be effective in probing the conceptual understanding of our students.

  12. Using Problematizing Ability to Predict Student Performance in a First Course in Computer Programming

    ERIC Educational Resources Information Center

    Schuyler, Stanley TenEyck

    2008-01-01

    Problem solving can be thought of in two phases: the first phase is problem formulation and the second solution development. Problem formulation is the process of identifying a problem or opportunity in a situation. Problem Formulation Ability, or PFA, is the ability to perform this process. This research investigated a method to assess PFA and…

  13. The Insulation of Copper Wire by the Electrostatic Coating Process.

    DTIC Science & Technology

    1983-06-30

    fluorinated ethylene propylene), ECFTE (ethylene- chlorotrifluoro ethylene), and PFA (perfluoroalkoxy resin). Another material of interest with good...Fluoroplastics - Fluoroplastics are a family of polymers with the general paraffin structure that have some or all of the hydrogen replaced by fluorine ...ETFE (ethylene-tetrafluoroethylene copolymer), PFA (perfluoroalkoxy resin), ECTFE (ethylene-chlorotrifluoroethylene), and FEP ( fluorinated ethylene

  14. Department of Defense In-House RDT&E Activities, FY97, Management Analysis Report

    DTIC Science & Technology

    1998-05-01

    NUMBER (p48o9*VTL# M -MiFAtjo T-LIc~oLoG/-rA44J rnot) -refj PfA cA4J P04-3 Di 9c mTTf130D. c. 7 l q I - o? o __ _ _ __ _ _ _ S. SPONSORING I MONITORIWO...and active fiber Bragg grating sensor readout systems with ultra-high measurement sensitivity. Title: Evaluation of Dye Sorption Phenomena on Nano-Sized

  15. Confirmatory factor analysis using Microsoft Excel.

    PubMed

    Miles, Jeremy N V

    2005-11-01

    This article presents a method for using Microsoft (MS) Excel for confirmatory factor analysis (CFA). CFA is often seen as an impenetrable technique, and thus, when it is taught, there is frequently little explanation of the mechanisms or underlying calculations. The aim of this article is to demonstrate that this is not the case; it is relatively straightforward to produce a spreadsheet in MS Excel that can carry out simple CFA. It is possible, with few or no programming skills, to effectively program a CFA analysis and, thus, to gain insight into the workings of the procedure.

  16. Docosahexaenoic Acid Protects from Dendritic Pathology in an Alzheimer’s Disease Mouse Model

    PubMed Central

    Calon, Frédéric; Lim, Giselle P.; Yang, Fusheng; Morihara, Takashi; Teter, Bruce; Ubeda, Oliver; Rostaing, Phillippe; Triller, Antoine; Salem, Norman; Ashe, Karen H.; Frautschy, Sally A.; Cole, Greg M.

    2005-01-01

    Learning and memory depend on dendritic spine actin assembly and docosahexaenoic acid (DHA), an essential n-3 (omega-3) polyunsaturated fatty acid (PFA). High DHA consumption is associated with reduced Alzheimer’s disease (AD) risk, yet mechanisms and therapeutic potential remain elusive. Here, we report that reduction of dietary n-3 PFA in an AD mouse model resulted in 80%–90% losses of the p85α subunit of phosphatidylinositol 3-kinase and the postsynaptic actin-regulating protein drebrin, as in AD brain. The loss of postsynaptic proteins was associated with increased oxidation, without concomitant neuron or pre-synaptic protein loss. N-3 PFA depletion increased caspase-cleaved actin, which was localized in dendrites ultrastructurally. Treatment of n-3 PFA-restricted mice with DHA protected against these effects and behavioral deficits and increased antiapoptotic BAD phosphorylation. Since n-3 PFAs are essential for p85-mediated CNS insulin signaling and selective protection of postsynaptic proteins, these findings have implications for neurodegenerative diseases where synaptic loss is critical, especially AD. PMID:15339646

  17. The impact of wildland fires on calcareous Mediterranean pedosystems (Sardinia, Italy) - An integrated multiple approach.

    PubMed

    Capra, Gian Franco; Tidu, Simona; Lovreglio, Raffaella; Certini, Giacomo; Salis, Michele; Bacciu, Valentina; Ganga, Antonio; Filzmoser, Peter

    2018-05-15

    Sardinia (Italy), the second largest island of the Mediterranean Sea, is a fire-prone land. Most Sardinian environments over time were shaped by fire, but some of them are too intrinsically fragile to withstand the currently increasing fire frequency. Calcareous pedoenvironments represent a significant part of Mediterranean areas, and require important efforts to prevent long-lasting degradation from fire. The aim of this study was to assess through an integrated multiple approach the impact of a single and highly severe wildland fire on limestone-derived soils. For this purpose, we selected two recently burned sites, Sant'Antioco and Laconi. Soil was sampled from 80 points on a 100×100m grid - 40 in the burned area and 40 in unburned one - and analyzed for particle size fractions, pH, electrical conductivity, organic carbon, total N, total P, and water repellency (WR). Fire behavior (surface rate of spread (ROS), fireline intensity (FLI), flame length (FL)) was simulated by BehavePlus 5.0.5 software. Comparisons between burned and unburned areas were done through ANOVA as well as deterministic and stochastic interpolation techniques; multiple correlations among parameters were evaluated by principal factor analysis (PFA) and differences/similarities between areas by principal component analysis (PCA). In both sites, fires were characterized by high severity and determined significant changes to some soil properties. The PFA confirmed the key ecological role played by fire in both sites, with the variability of a four-modeled components mainly explained by fire parameters, although the induced changes on soils were mainly site-specific. The PCA revealed the presence of two main "driving factors": slope (in Sant'Antioco), which increased the magnitude of ROS and FLI; and soil properties (in Laconi), which mostly affected FL. In both sites, such factors played a direct role in differentiating fire behavior and sites, while they played an indirect role in determining

  18. Testing all six person-oriented principles in dynamic factor analysis.

    PubMed

    Molenaar, Peter C M

    2010-05-01

    All six person-oriented principles identified by Sterba and Bauer's Keynote Article can be tested by means of dynamic factor analysis in its current form. In particular, it is shown how complex interactions and interindividual differences/intraindividual change can be tested in this way. In addition, the necessity to use single-subject methods in the analysis of developmental processes is emphasized, and attention is drawn to the possibility to optimally treat developmental psychopathology by means of new computational techniques that can be integrated with dynamic factor analysis.

  19. Reexamination of effects of paraformaldehyde on tissues around tapholes in sugar maple trees

    Treesearch

    David R. Houston; J. Chris Fagan

    1997-01-01

    Pellets containing paraformaldehyde (PFA) are sometimes placed behind spouts in tapped sugar maples to prolong sapflow and increase the yield of sap used to make maple syrup.The practice is controversial because the chemical has been shown to promote decay and is reported to cause cambial dieback around tapholes.This study reexamined the effects of PFA on tapped sugar...

  20. 40 CFR 280.40 - General requirements for all UST systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... release detection that: (1) Can detect a release from any portion of the tank and the connected... shown in the table) with a probability of detection (Pd) of 0.95 and a probability of false alarm (Pfa) of 0.05. Method Section Date after which Pd/Pfa must be demonstrated Manual Tank Gauging 280.43(b...

  1. 40 CFR 280.40 - General requirements for all UST systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... release detection that: (1) Can detect a release from any portion of the tank and the connected... shown in the table) with a probability of detection (Pd) of 0.95 and a probability of false alarm (Pfa) of 0.05. Method Section Date after which Pd/Pfa must be demonstrated Manual Tank Gauging 280.43(b...

  2. 40 CFR 280.40 - General requirements for all UST systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... release detection that: (1) Can detect a release from any portion of the tank and the connected... shown in the table) with a probability of detection (Pd) of 0.95 and a probability of false alarm (Pfa) of 0.05. Method Section Date after which Pd/Pfa must be demonstrated Manual Tank Gauging 280.43(b...

  3. 40 CFR 280.40 - General requirements for all UST systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... release detection that: (1) Can detect a release from any portion of the tank and the connected... shown in the table) with a probability of detection (Pd) of 0.95 and a probability of false alarm (Pfa) of 0.05. Method Section Date after which Pd/Pfa must be demonstrated Manual Tank Gauging 280.43(b...

  4. 40 CFR 280.40 - General requirements for all UST systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... release detection that: (1) Can detect a release from any portion of the tank and the connected... shown in the table) with a probability of detection (Pd) of 0.95 and a probability of false alarm (Pfa) of 0.05. Method Section Date after which Pd/Pfa must be demonstrated Manual Tank Gauging 280.43(b...

  5. Exploratory factor analysis of borderline personality disorder criteria in hospitalized adolescents.

    PubMed

    Becker, Daniel F; McGlashan, Thomas H; Grilo, Carlos M

    2006-01-01

    The authors examined the factor structure of borderline personality disorder (BPD) in hospitalized adolescents and also sought to add to the theoretical and clinical understanding of any homogeneous components by determining whether they may be related to specific forms of Axis I pathology. Subjects were 123 adolescent inpatients, who were reliably assessed with structured diagnostic interviews for Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition Axes I and II disorders. Exploratory factor analysis identified BPD components, and logistic regression analyses tested whether these components were predictive of specific Axis I disorders. Factor analysis revealed a 4-factor solution that accounted for 67.0% of the variance. Factor 1 ("suicidal threats or gestures" and "emptiness or boredom") predicted depressive disorders and alcohol use disorders. Factor 2 ("affective instability," "uncontrolled anger," and "identity disturbance") predicted anxiety disorders and oppositional defiant disorder. Factor 3 ("unstable relationships" and "abandonment fears") predicted only anxiety disorders. Factor 4 ("impulsiveness" and "identity disturbance") predicted conduct disorder and substance use disorders. Exploratory factor analysis of BPD criteria in adolescent inpatients revealed 4 BPD factors that appear to differ from those reported for similar studies of adults. The factors represent components of self-negation, irritability, poorly modulated relationships, and impulsivity--each of which is associated with characteristic Axis I pathology. These findings shed light on the nature of BPD in adolescents and may also have implications for treatment.

  6. Exploratory factor analysis of the Oral Health Impact Profile.

    PubMed

    John, M T; Reissmann, D R; Feuerstahler, L; Waller, N; Baba, K; Larsson, P; Celebić, A; Szabo, G; Rener-Sitar, K

    2014-09-01

    Although oral health-related quality of life (OHRQoL) as measured by the Oral Health Impact Profile (OHIP) is thought to be multidimensional, the nature of these dimensions is not known. The aim of this report was to explore the dimensionality of the OHIP using the Dimensions of OHRQoL (DOQ) Project, an international study of general population subjects and prosthodontic patients. Using the project's Learning Sample (n = 5173), we conducted an exploratory factor analysis on the 46 OHIP items not specifically referring to dentures for 5146 subjects with sufficiently complete data. The first eigenvalue (27·0) of the polychoric correlation matrix was more than ten times larger than the second eigenvalue (2·6), suggesting the presence of a dominant, higher-order general factor. Follow-up analyses with Horn's parallel analysis revealed a viable second-order, four-factor solution. An oblique rotation of this solution revealed four highly correlated factors that we named Oral Function, Oro-facial Pain, Oro-facial Appearance and Psychosocial Impact. These four dimensions and the strong general factor are two viable hypotheses for the factor structure of the OHIP. © 2014 John Wiley & Sons Ltd.

  7. Factor analysis of an instrument to measure the impact of disease on daily life.

    PubMed

    Pedrosa, Rafaela Batista Dos Santos; Rodrigues, Roberta Cunha Matheus; Padilha, Kátia Melissa; Gallani, Maria Cecília Bueno Jayme; Alexandre, Neusa Maria Costa

    2016-01-01

    to verify the structure of factors of an instrument to measure the Heart Valve Disease Impact on Daily Life (IDCV) when applied to coronary artery disease patients. the study included 153 coronary artery disease patients undergoing outpatient follow-up care. The IDCV structure of factors was initially assessed by means of confirmatory factor analysis and, subsequently, by exploratory factor analysis. The Varimax rotation method was used to estimate the main components of analysis, eigenvalues greater than one for extraction of factors, and factor loading greater than 0.40 for selection of items. Internal consistency was estimated using Cronbach's alpha coefficient. confirmatory factor analysis did not confirm the original structure of factors of the IDCV. Exploratory factor analysis showed three dimensions, which together explained 78% of the measurement variance. future studies with expansion of case selection are necessary to confirm the IDCV new structure of factors.

  8. A human factors analysis of EVA time requirements

    NASA Technical Reports Server (NTRS)

    Pate, D. W.

    1996-01-01

    Human Factors Engineering (HFE), also known as Ergonomics, is a discipline whose goal is to engineer a safer, more efficient interface between humans and machines. HFE makes use of a wide range of tools and techniques to fulfill this goal. One of these tools is known as motion and time study, a technique used to develop time standards for given tasks. A human factors motion and time study was initiated with the goal of developing a database of EVA task times and a method of utilizing the database to predict how long an ExtraVehicular Activity (EVA) should take. Initial development relied on the EVA activities performed during the STS-61 mission (Hubble repair). The first step of the analysis was to become familiar with EVAs and with the previous studies and documents produced on EVAs. After reviewing these documents, an initial set of task primitives and task time modifiers was developed. Videotaped footage of STS-61 EVAs were analyzed using these primitives and task time modifiers. Data for two entire EVA missions and portions of several others, each with two EVA astronauts, was collected for analysis. Feedback from the analysis of the data will be used to further refine the primitives and task time modifiers used. Analysis of variance techniques for categorical data will be used to determine which factors may, individually or by interactions, effect the primitive times and how much of an effect they have.

  9. Tensor-Dictionary Learning with Deep Kruskal-Factor Analysis

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

    Stevens, Andrew J.; Pu, Yunchen; Sun, Yannan

    We introduce new dictionary learning methods for tensor-variate data of any order. We represent each data item as a sum of Kruskal decomposed dictionary atoms within the framework of beta-process factor analysis (BPFA). Our model is nonparametric and can infer the tensor-rank of each dictionary atom. This Kruskal-Factor Analysis (KFA) is a natural generalization of BPFA. We also extend KFA to a deep convolutional setting and develop online learning methods. We test our approach on image processing and classification tasks achieving state of the art results for 2D & 3D inpainting and Caltech 101. The experiments also show that atom-rankmore » impacts both overcompleteness and sparsity.« less

  10. Factor Analysis of Drawings: Application to College Student Models of the Greenhouse Effect

    ERIC Educational Resources Information Center

    Libarkin, Julie C.; Thomas, Stephen R.; Ording, Gabriel

    2015-01-01

    Exploratory factor analysis was used to identify models underlying drawings of the greenhouse effect made by over 200 entering university freshmen. Initial content analysis allowed deconstruction of drawings into salient features, with grouping of these features via factor analysis. A resulting 4-factor solution explains 62% of the data variance,…

  11. Confirmatory factor analysis applied to the Force Concept Inventory

    NASA Astrophysics Data System (ADS)

    Eaton, Philip; Willoughby, Shannon D.

    2018-06-01

    In 1995, Huffman and Heller used exploratory factor analysis to draw into question the factors of the Force Concept Inventory (FCI). Since then several papers have been published examining the factors of the FCI on larger sets of student responses and understandable factors were extracted as a result. However, none of these proposed factor models have been verified to not be unique to their original sample through the use of independent sets of data. This paper seeks to confirm the factor models proposed by Scott et al. in 2012, and Hestenes et al. in 1992, as well as another expert model proposed within this study through the use of confirmatory factor analysis (CFA) and a sample of 20 822 postinstruction student responses to the FCI. Upon application of CFA using the full sample, all three models were found to fit the data with acceptable global fit statistics. However, when CFA was performed using these models on smaller sample sizes the models proposed by Scott et al. and Eaton and Willoughby were found to be far more stable than the model proposed by Hestenes et al. The goodness of fit of these models to the data suggests that the FCI can be scored on factors that are not unique to a single class. These scores could then be used to comment on how instruction methods effect the performance of students along a single factor and more in-depth analyses of curriculum changes may be possible as a result.

  12. Principles and practical procedures for acute psychological first aid training for personnel without mental health experience.

    PubMed

    Everly, George S; Flynn, Brian W

    2006-01-01

    Most authorities agree that mass disasters leave in their wake a need for some form of acute mental health services. However, a review of current literature on crisis intervention and disaster mental health reveals differing points of view on the methods that should be employed (Raphael, 1986; NIMH, 2002). Nevertheless, there appears to be virtual universal endorsement, by relevant authorities, of the value of acute "psychological first aid" (American Psychiatric Association, 1954; USDHHS, 2004; Raphael, 1986; NIMH, 2002; Institute of Medicine, 2003; WHO, 2003; DoD/VAPTSD, 2004; Ritchie, et al., 2004; Friedman, Hamblin, Foa, & Charney, 2004). Psychological first aid (PFA), as an acute mental health intervention, seems uniquely applicable to public health settings, the workplace, the military, mass disaster venues, and even the demands of more well circumscribed critical incidents, e.g., dealing with the psychological aftermath of accidents, robberies, suicide, homicide, or community violence. In this document, we shall introduce the notion of psychological first aid (PFA) as one aspect of a psychological continuum of care, offer a rudimentary definition of PFA, and provide the reader with a practicalframework for its implementation utilizing the individual psychological first aid (iPFA)format. The goal of this paper is to better prepare public health, public safety, and other disaster response personnel who do not possess formal clinical mental health degrees or specialized training to provide iPFA services to primary and secondary disaster victims.

  13. Characterization of Thermal, Mechanical and Tribological Properties of Fluoropolymer Composite Coatings

    NASA Astrophysics Data System (ADS)

    He, Y.; Farokhzadeh, K.; Edrisy, A.

    2017-04-01

    Perfluoroalkoxy (PFA) is a potential polymer coating material for low-temperature waste heat recovery in heat exchangers. Nonetheless, poor thermal conductivity, low strength and susceptibility to surface degradation by erosion/wear pose restrictions in its application. In this study, four types of fillers, namely graphite, silicon carbide, alumina and boron nitride, were introduced to enhance the thermal, mechanical and tribological properties in PFA coatings. The thermal diffusivity and specific heat capacity of the composites (reinforced with 20 wt.% filler) were also measured using laser flash and differential scanning calorimetry techniques, respectively. The results indicated that the addition of graphite or boron nitride increased the thermal conductivity of PFA by at least 2.8 orders of magnitude, while the composites with the same weight fraction of alumina or silicon carbide showed 20-80% rise in thermal conductivity. The micromechanical deformation and tribological behavior of composite coatings, electrostatically sprayed on steel substrates, were investigated by means of instrumented indentation and scratch tests. The deformation response and friction characteristics were investigated, and the failure mechanisms were identified. Surface hardness, roughness and structure of fillers influenced the sliding performance of the composite coatings. PFA coatings filled with Al2O3 or SiC particles showed high load-bearing capacity under sliding conditions. Conversely, BN- and graphite-filled PFA coatings exhibited lower interfacial adhesion to steel substrate and were prone to failure at relatively lower applied loads.

  14. Toward Reflective Judgment in Exploratory Factor Analysis Decisions: Determining the Extraction Method and Number of Factors To Retain.

    ERIC Educational Resources Information Center

    Knight, Jennifer L.

    This paper considers some decisions that must be made by the researcher conducting an exploratory factor analysis. The primary purpose is to aid the researcher in making informed decisions during the factor analysis instead of relying on defaults in statistical programs or traditions of previous researchers. Three decision areas are addressed.…

  15. SEPARABLE FACTOR ANALYSIS WITH APPLICATIONS TO MORTALITY DATA

    PubMed Central

    Fosdick, Bailey K.; Hoff, Peter D.

    2014-01-01

    Human mortality data sets can be expressed as multiway data arrays, the dimensions of which correspond to categories by which mortality rates are reported, such as age, sex, country and year. Regression models for such data typically assume an independent error distribution or an error model that allows for dependence along at most one or two dimensions of the data array. However, failing to account for other dependencies can lead to inefficient estimates of regression parameters, inaccurate standard errors and poor predictions. An alternative to assuming independent errors is to allow for dependence along each dimension of the array using a separable covariance model. However, the number of parameters in this model increases rapidly with the dimensions of the array and, for many arrays, maximum likelihood estimates of the covariance parameters do not exist. In this paper, we propose a submodel of the separable covariance model that estimates the covariance matrix for each dimension as having factor analytic structure. This model can be viewed as an extension of factor analysis to array-valued data, as it uses a factor model to estimate the covariance along each dimension of the array. We discuss properties of this model as they relate to ordinary factor analysis, describe maximum likelihood and Bayesian estimation methods, and provide a likelihood ratio testing procedure for selecting the factor model ranks. We apply this methodology to the analysis of data from the Human Mortality Database, and show in a cross-validation experiment how it outperforms simpler methods. Additionally, we use this model to impute mortality rates for countries that have no mortality data for several years. Unlike other approaches, our methodology is able to estimate similarities between the mortality rates of countries, time periods and sexes, and use this information to assist with the imputations. PMID:25489353

  16. Critical Factors Analysis for Offshore Software Development Success by Structural Equation Modeling

    NASA Astrophysics Data System (ADS)

    Wada, Yoshihisa; Tsuji, Hiroshi

    In order to analyze the success/failure factors in offshore software development service by the structural equation modeling, this paper proposes to follow two approaches together; domain knowledge based heuristic analysis and factor analysis based rational analysis. The former works for generating and verifying of hypothesis to find factors and causalities. The latter works for verifying factors introduced by theory to build the model without heuristics. Following the proposed combined approaches for the responses from skilled project managers of the questionnaire, this paper found that the vendor property has high causality for the success compared to software property and project property.

  17. Physics Metacognition Inventory Part Ii: Confirmatory Factor Analysis and Rasch Analysis

    ERIC Educational Resources Information Center

    Taasoobshirazi, Gita; Bailey, MarLynn; Farley, John

    2015-01-01

    The Physics Metacognition Inventory was developed to measure physics students' metacognition for problem solving. In one of our earlier studies, an exploratory factor analysis provided evidence of preliminary construct validity, revealing six components of students' metacognition when solving physics problems including knowledge of cognition,…

  18. Connectivism in Postsecondary Online Courses: An Exploratory Factor Analysis

    ERIC Educational Resources Information Center

    Hogg, Nanette; Lomicky, Carol S.

    2012-01-01

    This study explores 465 postsecondary students' experiences in online classes through the lens of connectivism. Downes' 4 properties of connectivism (diversity, autonomy, interactivity, and openness) were used as the study design. An exploratory factor analysis was performed. This study found a 4-factor solution. Subjects indicated that autonomy…

  19. Sparse multivariate factor analysis regression models and its applications to integrative genomics analysis.

    PubMed

    Zhou, Yan; Wang, Pei; Wang, Xianlong; Zhu, Ji; Song, Peter X-K

    2017-01-01

    The multivariate regression model is a useful tool to explore complex associations between two kinds of molecular markers, which enables the understanding of the biological pathways underlying disease etiology. For a set of correlated response variables, accounting for such dependency can increase statistical power. Motivated by integrative genomic data analyses, we propose a new methodology-sparse multivariate factor analysis regression model (smFARM), in which correlations of response variables are assumed to follow a factor analysis model with latent factors. This proposed method not only allows us to address the challenge that the number of association parameters is larger than the sample size, but also to adjust for unobserved genetic and/or nongenetic factors that potentially conceal the underlying response-predictor associations. The proposed smFARM is implemented by the EM algorithm and the blockwise coordinate descent algorithm. The proposed methodology is evaluated and compared to the existing methods through extensive simulation studies. Our results show that accounting for latent factors through the proposed smFARM can improve sensitivity of signal detection and accuracy of sparse association map estimation. We illustrate smFARM by two integrative genomics analysis examples, a breast cancer dataset, and an ovarian cancer dataset, to assess the relationship between DNA copy numbers and gene expression arrays to understand genetic regulatory patterns relevant to the disease. We identify two trans-hub regions: one in cytoband 17q12 whose amplification influences the RNA expression levels of important breast cancer genes, and the other in cytoband 9q21.32-33, which is associated with chemoresistance in ovarian cancer. © 2016 WILEY PERIODICALS, INC.

  20. Factor analysis of the Hamilton Depression Rating Scale in Parkinson's disease.

    PubMed

    Broen, M P G; Moonen, A J H; Kuijf, M L; Dujardin, K; Marsh, L; Richard, I H; Starkstein, S E; Martinez-Martin, P; Leentjens, A F G

    2015-02-01

    Several studies have validated the Hamilton Depression Rating Scale (HAMD) in patients with Parkinson's disease (PD), and reported adequate reliability and construct validity. However, the factorial validity of the HAMD has not yet been investigated. The aim of our analysis was to explore the factor structure of the HAMD in a large sample of PD patients. A principal component analysis of the 17-item HAMD was performed on data of 341 PD patients, available from a previous cross sectional study on anxiety. An eigenvalue ≥1 was used to determine the number of factors. Factor loadings ≥0.4 in combination with oblique rotations were used to identify which variables made up the factors. Kaiser-Meyer-Olkin measure (KMO), Cronbach's alpha, Bartlett's test, communality, percentage of non-redundant residuals and the component correlation matrix were computed to assess factor validity. KMO verified the sample's adequacy for factor analysis and Cronbach's alpha indicated a good internal consistency of the total scale. Six factors had eigenvalues ≥1 and together explained 59.19% of the variance. The number of items per factor varied from 1 to 6. Inter-item correlations within each component were low. There was a high percentage of non-redundant residuals and low communality. This analysis demonstrates that the factorial validity of the HAMD in PD is unsatisfactory. This implies that the scale is not appropriate for studying specific symptom domains of depression based on factorial structure in a PD population. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Evaluating voice characteristics of first-year acting students in Israel: factor analysis.

    PubMed

    Amir, Ofer; Primov-Fever, Adi; Kushnir, Tami; Kandelshine-Waldman, Osnat; Wolf, Michael

    2013-01-01

    Acting students require diverse, high-quality, and high-intensity vocal performance from early stages of their training. Demanding vocal activities, before developing the appropriate vocal skills, put them in high risk for developing vocal problems. A retrospective analysis of voice characteristics of first-year acting students using several voice evaluation tools. A total of 79 first-year acting students (55 women and 24 men) were assigned into two study groups: laryngeal findings (LFs) and no laryngeal findings, based on stroboscopic findings. Their voice characteristics were evaluated using acoustic analysis, aerodynamic examination, perceptual scales, and self-report questionnaires. Results obtained from each set of measures were examined using a factor analysis approach. Significant differences between the two groups were found for a single fundamental frequency (F(0))-Regularity factor; a single Grade, Roughness, Breathiness, Asthenia, Strain perceptual factor; and the three self-evaluation factors. Gender differences were found for two acoustic analysis factors, which were based on F(0) and its derivatives, namely an aerodynamic factor that represents expiratory volume measurements and a single self-evaluation factor that represents the tendency to seek therapy. Approximately 50% of the first-year acting students had LFs. These students differed from their peers in the control group in a single acoustic analysis factor, as well as perceptual and self-report factors. No group differences, however, were found for the aerodynamic factors. Early laryngeal examination and voice evaluation of future professional voice users could provide a valuable individual baseline, to which later examinations could be compared, and assist in providing personally tailored treatment. Copyright © 2013 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

  2. Permeation Testing of Materials With Chemical Agents or Simulants (Swatch Testing)

    DTIC Science & Technology

    2013-08-05

    through a protective clothing material on a molecular level. Permeation involves the following: (1) sorption of molecules of the chemical into the...de Nemours and Company, Wilmington, Delaware), Teflon perfluoro- alkoxy ( PFA ), and Teflon polytetrafluoroethylene (PTFE). c. In all cases, only...pamphlet PCM positive control material PFA perfluoroalkoxy pH negative ion activity POL petroleum, oil, and lubricants PQL program quantification

  3. Establishing Evidence for Internal Structure Using Exploratory Factor Analysis

    ERIC Educational Resources Information Center

    Watson, Joshua C.

    2017-01-01

    Exploratory factor analysis (EFA) is a data reduction technique used to condense data into smaller sets of summary variables by identifying underlying factors potentially accounting for patterns of collinearity among said variables. Using an illustrative example, the 5 general steps of EFA are described with best practices for decision making…

  4. An Evaluation on Factors Influencing Decision making for Malaysia Disaster Management: The Confirmatory Factor Analysis Approach

    NASA Astrophysics Data System (ADS)

    Zubir, S. N. A.; Thiruchelvam, S.; Mustapha, K. N. M.; Che Muda, Z.; Ghazali, A.; Hakimie, H.

    2017-12-01

    For the past few years, natural disaster has been the subject of debate in disaster management especially in flood disaster. Each year, natural disaster results in significant loss of life, destruction of homes and public infrastructure, and economic hardship. Hence, an effective and efficient flood disaster management would assure non-futile efforts for life saving. The aim of this article is to examine the relationship between approach, decision maker, influence factor, result, and ethic to decision making for flood disaster management in Malaysia. The key elements of decision making in the disaster management were studied based on the literature. Questionnaire surveys were administered among lead agencies at East Coast of Malaysia in the state of Kelantan and Pahang. A total of 307 valid responses had been obtained for further analysis. Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) were carried out to analyse the measurement model involved in the study. The CFA for second-order reflective and first-order reflective measurement model indicates that approach, decision maker, influence factor, result, and ethic have a significant and direct effect on decision making during disaster. The results from this study showed that decision- making during disaster is an important element for disaster management to necessitate a successful collaborative decision making. The measurement model is accepted to proceed with further analysis known as Structural Equation Modeling (SEM) and can be assessed for the future research.

  5. Analysis of the influencing factors of global energy interconnection development

    NASA Astrophysics Data System (ADS)

    Zhang, Yi; He, Yongxiu; Ge, Sifan; Liu, Lin

    2018-04-01

    Under the background of building global energy interconnection and achieving green and low-carbon development, this paper grasps a new round of energy restructuring and the trend of energy technology change, based on the present situation of global and China's global energy interconnection development, established the index system of the impact of global energy interconnection development factors. A subjective and objective weight analysis of the factors affecting the development of the global energy interconnection was conducted separately by network level analysis and entropy method, and the weights are summed up by the method of additive integration, which gives the comprehensive weight of the influencing factors and the ranking of their influence.

  6. Examining Evolving Performance on the Force Concept Inventory Using Factor Analysis

    ERIC Educational Resources Information Center

    Semak, M. R.; Dietz, R. D.; Pearson, R. H.; Willis, C. W

    2017-01-01

    The application of factor analysis to the "Force Concept Inventory" (FCI) has proven to be problematic. Some studies have suggested that factor analysis of test results serves as a helpful tool in assessing the recognition of Newtonian concepts by students. Other work has produced at best ambiguous results. For the FCI administered as a…

  7. A Markov Chain Monte Carlo Approach to Confirmatory Item Factor Analysis

    ERIC Educational Resources Information Center

    Edwards, Michael C.

    2010-01-01

    Item factor analysis has a rich tradition in both the structural equation modeling and item response theory frameworks. The goal of this paper is to demonstrate a novel combination of various Markov chain Monte Carlo (MCMC) estimation routines to estimate parameters of a wide variety of confirmatory item factor analysis models. Further, I show…

  8. Improving Your Exploratory Factor Analysis for Ordinal Data: A Demonstration Using FACTOR

    ERIC Educational Resources Information Center

    Baglin, James

    2014-01-01

    Exploratory factor analysis (EFA) methods are used extensively in the field of assessment and evaluation. Due to EFA's widespread use, common methods and practices have come under close scrutiny. A substantial body of literature has been compiled highlighting problems with many of the methods and practices used in EFA, and, in response, many…

  9. Factor analysis of the contextual fine motor questionnaire in children.

    PubMed

    Lin, Chin-Kai; Meng, Ling-Fu; Yu, Ya-Wen; Chen, Che-Kuo; Li, Kuan-Hua

    2014-02-01

    Most studies treat fine motor as one subscale in a developmental test, hence, further factor analysis of fine motor has not been conducted. In fact, fine motor has been treated as a multi-dimensional domain from both clinical and theoretical perspectives, and therefore to know its factors would be valuable. The aim of this study is to analyze the internal consistency and factor validity of the Contextual Fine Motor Questionnaire (CFMQ). Based on the ecological observation and literature, the Contextual Fine Motor Questionnaire (CFMQ) was developed and includes 5 subscales: Pen Control, Tool Use During Handicraft Activities, the Use of Dining Utensils, Connecting and Separating during Dressing and Undressing, and Opening Containers. The main purpose of this study is to establish the factorial validity of the CFMQ through conducting this factor analysis study. Among 1208 questionnaires, 904 were successfully completed. Data from the children's CFMQ submitted by primary care providers was analyzed, including 485 females (53.6%) and 419 males (46.4%) from grades 1 to 5, ranging in age from 82 to 167 months (M=113.9, SD=16.3). Cronbach's alpha was used to measure internal consistency and explorative factor analysis was applied to test the five factor structures within the CFMQ. Results showed that Cronbach's alpha coefficient of the CFMQ for 5 subscales ranged from .77 to .92 and all item-total correlations with corresponding subscales were larger than .4 except one item. The factor loading of almost all items classified to their factor was larger than .5 except 3 items. There were five factors, explaining a total of 62.59% variance for the CFMQ. In conclusion, the remaining 24 items in the 5 subscales of the CFMQ had appropriate internal consistency, test-retest reliability and construct validity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Assessing suicide risk among callers to crisis hotlines: a confirmatory factor analysis.

    PubMed

    Witte, Tracy K; Gould, Madelyn S; Munfakh, Jimmie Lou Harris; Kleinman, Marjorie; Joiner, Thomas E; Kalafat, John

    2010-09-01

    Our goal was to investigate the factor structure of a risk assessment tool utilized by suicide hotlines and to determine the predictive validity of the obtained factors in predicting subsequent suicidal behavior. We conducted an Exploratory Factor Analysis (EFA), an EFA in a Confirmatory Factor Analysis (EFA/CFA) framework, and a CFA on independent subsamples derived from a total sample of 1,085. Similar to previous studies, we found consistent evidence for a two-factor solution, with one factor representing a more pernicious form of suicide risk (i.e., Resolved Plans and Preparations; RPP) and one factor representing milder suicidal ideation (i.e., Suicidal Desire and Ideation; SDI). The RPP factor trended toward being more predictive of suicidal ideation at follow-up than the SDI factor. (c) 2010 Wiley Periodicals, Inc.

  11. Psychological first aid training for Lebanese field workers in the emergency context of the Syrian refugees in Lebanon.

    PubMed

    Akoury-Dirani, Leyla; Sahakian, Tina S; Hassan, Fahed Y; Hajjar, Ranya V; El Asmar, Khalil

    2015-11-01

    The Syrian refugee crisis in Lebanon required a fast and efficient comprehensive rescue strategy. Professionals working in emergency response were neither prepared to provide psychological first aid nor prepared to screen for mental health disorders in child refugees. This article examines the efficacy of a national training program in psychological first aid (PFA) to enhance the readiness of mental health field workers in the Syrian refugee response. Participant (N = 109) were recruited from Lebanese ministries and nongovernmental organizations. They received a 2.5-day training on PFA and on screening for mental health disorders in children. Their knowledge and perceived readiness were assessed before the training, immediately after the training, and 1 month after the training using 2 evaluation forms. Evaluation Form A was a multiple choice questionnaire composed of 20 questions and created on the basis of the content of the training, and Evaluation Form B was a Likert-type scale of 20 items created based on the core components of PFA. The data of 60 participants were analyzed. The results showed a significant increase in knowledge and readiness, specifically on the components related to the principles and techniques of PFA. (c) 2015 APA, all rights reserved).

  12. Adherence of volatile propofol to various types of plastic tubing.

    PubMed

    Maurer, F; Lorenz, D J; Pielsticker, G; Volk, T; Sessler, D I; Baumbach, J I; Kreuer, S

    2017-01-23

    Propofol is an intravenous anesthetic. Currently, it is not possible to routinely measure blood concentration of the drug in real time. However, multi-capillary column ion-mobility spectrometry of exhaled gas can estimate blood propofol concentration. Unfortunately, adhesion of volatile propofol on plastic materials complicates measurements. Therefore, it is necessary to consider the extent to which volatile propofol adheres to various plastics used in sampling tubing. Perfluoralkoxy (PFA), polytetrafluorethylene (PTFE), polyurethane (PUR), silicone, and Tygon tubing were investigated in an experimental setting using a calibration gas generator (HovaCAL). Propofol gas was measured for one hour at 26 °C, 50 °C, and 90 °C tubing temperature. Test tubing segments were then flushed with N 2 to quantify desorption. PUR and Tygon sample tubing absorbed all volatile propofol. The silicone tubing reached the maximum propofol concentration after 119 min which was 29 min after propofol gas exposure stopped. The use of PFA or PTFE tubing produced comparable and reasonably accurate propofol measurements. The desaturation time for the PFA was 10 min shorter at 26 °C than for PTFE. PFA tubing thus seems most suitable for measurement of volatile propofol, with PTFE as an alternative.

  13. Factor analysis of serogroups botanica and aurisina of Leptospira biflexa.

    PubMed

    Cinco, M

    1977-11-01

    Factor analysis is performed on serovars of Botanica and Aurisina serogroup of Leptospira biflexa. The results show the arrangement of main factors serovar and serogroup specific, as well as the antigens common with serovars of heterologous serogroups.

  14. Risk factors for baclofen pump infection in children: a multivariate analysis.

    PubMed

    Spader, Heather S; Bollo, Robert J; Bowers, Christian A; Riva-Cambrin, Jay

    2016-06-01

    OBJECTIVE Intrathecal baclofen infusion systems to manage severe spasticity and dystonia are associated with higher infection rates in children than in adults. Factors unique to this population, such as poor nutrition and physical limitations for pump placement, have been hypothesized as the reasons for this disparity. The authors assessed potential risk factors for infection in a multivariate analysis. METHODS Patients who underwent implantation of a programmable pump and intrathecal catheter for baclofen infusion at a single center between January 1, 2000, and March 1, 2012, were identified in this retrospective cohort study. The primary end point was infection. Potential risk factors investigated included preoperative (i.e., demographics, body mass index [BMI], gastrostomy tube, tracheostomy, previous spinal fusion), intraoperative (i.e., surgeon, antibiotics, pump size, catheter location), and postoperative (i.e., wound dehiscence, CSF leak, and number of revisions) factors. Univariate analysis was performed, and a multivariate logistic regression model was created to identify independent risk factors for infection. RESULTS A total of 254 patients were evaluated. The overall infection rate was 9.8%. Univariate analysis identified young age, shorter height, lower weight, dehiscence, CSF leak, and number of revisions within 6 months of pump placement as significantly associated with infection. Multivariate analysis identified young age, dehiscence, and number of revisions as independent risk factors for infection. CONCLUSIONS Young age, wound dehiscence, and number of revisions were independent risk factors for infection in this pediatric cohort. A low BMI and the presence of either a gastrostomy or tracheostomy were not associated with infection and may not be contraindications for this procedure.

  15. Incomplete inhibition of platelet function as assessed by the platelet function analyzer (PFA-100) identifies a subset of cardiovascular patients with high residual platelet response while on aspirin.

    PubMed

    Crescente, M; Mezzasoma, A M; Del Pinto, M; Palmerini, F; Di Castelnuovo, A; Cerletti, C; De Gaetano, G; Gresele, P

    2011-01-01

    Sixty-six patients with a history of ischemic events (myocardial infarction, unstable angina, or stroke) on chronic aspirin therapy were studied by different platelet function tests: 37 patients had suffered a recurrent event while on aspirin and 29 were without recurrences. Based on results from light transmission aggregometry (LTA) induced by arachidonic acid (AA) and serum TxB(2) both COX-1-dependent methods, only one patient could be identified as aspirin "resistant". However, when methods only partially-dependent on platelet COX-1 activity were considered, the prevalence of aspirin non-responders ranged, according to the different tests, from 0 to 52%. No difference was observed between patients with recurrences and those without. Among patients with recurrent events, those with an incomplete inhibition of platelet function, as assessed by the PFA-100, had significantly higher residual serum TxB(2) (2.4 ± 2.4 ng/mL vs 0.4 ± 0.1 ng/mL, p = 0.03), residual LTA-AA (9.2 ± 10.6% vs 2.0 ± 1.6%, p = 0.008), LTA-Coll (49.3 ± 14.6% vs 10.2 ± 8.3%, p = 0.007) and LTA-ADP (50.9 ± 16.2% vs 34.3 ± 11.0%, p = 0.04). In conclusion, laboratory tests solely exploring the AA-mediated pathway of platelet function, while being the most appropriate to detect the effect of aspirin on its pharmacologic target (platelet COX-1), may fail to reveal the functional interactions between minimal residual TxA(2) and additional stimuli or primers potentially leading to aspirin-insensitive platelet aggregation. High residual platelet response in platelet function tests only partially dependent on COX-1 may reveal a condition of persistent platelet reactivity in a subset of aspirin-treated patients characterizing them as a subgroup at higher vascular risk.

  16. Predicting Failure Progression and Failure Loads in Composite Open-Hole Tension Coupons

    NASA Technical Reports Server (NTRS)

    Arunkumar, Satyanarayana; Przekop, Adam

    2010-01-01

    Failure types and failure loads in carbon-epoxy [45n/90n/-45n/0n]ms laminate coupons with central circular holes subjected to tensile load are simulated using progressive failure analysis (PFA) methodology. The progressive failure methodology is implemented using VUMAT subroutine within the ABAQUS(TradeMark)/Explicit nonlinear finite element code. The degradation model adopted in the present PFA methodology uses an instantaneous complete stress reduction (COSTR) approach to simulate damage at a material point when failure occurs. In-plane modeling parameters such as element size and shape are held constant in the finite element models, irrespective of laminate thickness and hole size, to predict failure loads and failure progression. Comparison to published test data indicates that this methodology accurately simulates brittle, pull-out and delamination failure types. The sensitivity of the failure progression and the failure load to analytical loading rates and solvers precision is demonstrated.

  17. FACTOR 9.2: A Comprehensive Program for Fitting Exploratory and Semiconfirmatory Factor Analysis and IRT Models

    ERIC Educational Resources Information Center

    Lorenzo-Seva, Urbano; Ferrando, Pere J.

    2013-01-01

    FACTOR 9.2 was developed for three reasons. First, exploratory factor analysis (FA) is still an active field of research although most recent developments have not been incorporated into available programs. Second, there is now renewed interest in semiconfirmatory (SC) solutions as suitable approaches to the complex structures are commonly found…

  18. Ultrasound-enhanced bioscouring of greige cotton: regression analysis of process factors

    USDA-ARS?s Scientific Manuscript database

    Process factors of enzyme concentration, time, power and frequency were investigated for ultrasound-enhanced bioscouring of greige cotton. A fractional factorial experimental design and subsequent regression analysis of the process factors were employed to determine the significance of each factor a...

  19. Identifying influential factors of business process performance using dependency analysis

    NASA Astrophysics Data System (ADS)

    Wetzstein, Branimir; Leitner, Philipp; Rosenberg, Florian; Dustdar, Schahram; Leymann, Frank

    2011-02-01

    We present a comprehensive framework for identifying influential factors of business process performance. In particular, our approach combines monitoring of process events and Quality of Service (QoS) measurements with dependency analysis to effectively identify influential factors. The framework uses data mining techniques to construct tree structures to represent dependencies of a key performance indicator (KPI) on process and QoS metrics. These dependency trees allow business analysts to determine how process KPIs depend on lower-level process metrics and QoS characteristics of the IT infrastructure. The structure of the dependencies enables a drill-down analysis of single factors of influence to gain a deeper knowledge why certain KPI targets are not met.

  20. Isomer profiling of perfluorinated substances as a tool for source tracking: a review of early findings and future applications.

    PubMed

    Benskin, Jonathan P; De Silva, Amila O; Martin, Jonathan W

    2010-01-01

    The two major manufacturing techniques for perfluorochemicals can be distinguished based on the isomeric profile of their products. ECF (major use from 1950s to 2002) results in a product containing both linear and branched isomers, while telomerization (major use from 2002 to present) typically yields an isomerically pure, linear product. Among the most important question today, which has implication for future regulation of these chemicals, is to what extent human and environmental exposure is from historical products (i.e., ECF) versus currently manufactured fluorochemicals (i.e., telomer). Perfluoroalkyl-chain branching can also affect the physical and chemical properties of these chemicals, which may influence their environmental transport and degradation, partitioning, bioaccumulation, pharmacokinetics, and toxicity. Unless perfluorinated substances are considered as individual isomers, much of this information will be overlooked or missed altogether, which could potentially lead to inaccuracies in human and environmental risk assessments. In this review, we have highlighted novel findings, current knowledge gaps, and areas for improvement based on early experiments on the disposition of PFA and PFA-precursor isomers in the environment. We have also emphasized the wealth of information that can potentially be gleaned from future work in this area, which renders routine adoption of isomer-specific methodologies an attractive and logical next step in the progression of fluorochemicals analysis. However, despite vast improvements in recent years, a fast and comprehensive method capable of separating all major PFA and PFA-precursor isomers, while removing interferences is still required before these methods becomes routine in most labs. Purified and characterized standards of PFOA and PFOS that have isomer profiles consistent with those of historically produced (i.e., 3M) PFOS and PFOA are also required. The limited data available on PFA isomer profiles that

  1. Confirmatory Factor Analysis of the WISC-III with Child Psychiatric Inpatients.

    ERIC Educational Resources Information Center

    Tupa, David J.; Wright, Margaret O'Dougherty; Fristad, Mary A.

    1997-01-01

    Factor models of the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) for one, two, three, and four factors were tested using confirmatory factor analysis with a sample of 177 child psychiatric inpatients. The four-factor model proposed in the WISC-III manual provided the best fit to the data. (SLD)

  2. Fulfilling the Promise of Preschool for All: Insights into Issues Affecting Access for Selected Immigrant Groups in Chicago

    ERIC Educational Resources Information Center

    Adams, Gina; McDaniel, Marla

    2009-01-01

    Preschool for All (PFA) is a part-day (2.5 hours for up to five days a week) early childhood education program for 3- and 4-year-olds in Illinois. The program is voluntary to families and is designed to be a high-quality preschool option for all children--especially those at risk of academic failure. PFA was implemented in 2006 and is free to…

  3. Machine Translation Based Data Augmentation for Cantonese Keyword Spotting (Author’s Manuscript)

    DTIC Science & Technology

    2016-05-19

    for the key- word k at the specific threshold t is defined as ATWV (k, t) = 1− PFR(k, t)− C · PFA (k, t) (1) where C = 999.9 is a constant, PFR and... PFA are probabil- ities of miss and false accept, respectively. MTWV is com- puted as a maximal ATWV over all possible values of t. 4. RESULTS In this

  4. Efficient Computer Implementations of Fast Fourier Transforms.

    DTIC Science & Technology

    1980-12-01

    fit in computer? Yes, continue (9) Determine fastest algorithm between WFTA and PFA from Table 4.6. For N=420, WFTA PFA Mult 1296 2528 Add 11352 10956...real adds = 24tN/4 + 2(3tN/4) = 15tN/2 (G.8) 260 All odd prime C<ictors ciual to or (,rater than 5 iso the general transform section. Based on the

  5. Emotional experiences and motivating factors associated with fingerprint analysis.

    PubMed

    Charlton, David; Fraser-Mackenzie, Peter A F; Dror, Itiel E

    2010-03-01

    In this study, we investigated the emotional and motivational factors involved in fingerprint analysis in day-to-day routine case work and in significant and harrowing criminal investigations. Thematic analysis was performed on interviews with 13 experienced fingerprint examiners from a variety of law enforcement agencies. The data revealed factors relating to job satisfaction and the use of skill. Individual satisfaction related to catching criminals was observed; this was most notable in solving high profile, serious, or long-running cases. There were positive emotional effects associated with matching fingerprints and apparent fear of making errors. Finally, we found evidence for a need of cognitive closure in fingerprint examiner decision-making.

  6. Image-derived input function with factor analysis and a-priori information.

    PubMed

    Simončič, Urban; Zanotti-Fregonara, Paolo

    2015-02-01

    Quantitative PET studies often require the cumbersome and invasive procedure of arterial cannulation to measure the input function. This study sought to minimize the number of necessary blood samples by developing a factor-analysis-based image-derived input function (IDIF) methodology for dynamic PET brain studies. IDIF estimation was performed as follows: (a) carotid and background regions were segmented manually on an early PET time frame; (b) blood-weighted and tissue-weighted time-activity curves (TACs) were extracted with factor analysis; (c) factor analysis results were denoised and scaled using the voxels with the highest blood signal; (d) using population data and one blood sample at 40 min, whole-blood TAC was estimated from postprocessed factor analysis results; and (e) the parent concentration was finally estimated by correcting the whole-blood curve with measured radiometabolite concentrations. The methodology was tested using data from 10 healthy individuals imaged with [(11)C](R)-rolipram. The accuracy of IDIFs was assessed against full arterial sampling by comparing the area under the curve of the input functions and by calculating the total distribution volume (VT). The shape of the image-derived whole-blood TAC matched the reference arterial curves well, and the whole-blood area under the curves were accurately estimated (mean error 1.0±4.3%). The relative Logan-V(T) error was -4.1±6.4%. Compartmental modeling and spectral analysis gave less accurate V(T) results compared with Logan. A factor-analysis-based IDIF for [(11)C](R)-rolipram brain PET studies that relies on a single blood sample and population data can be used for accurate quantification of Logan-V(T) values.

  7. Factors that Affect Poverty Areas in North Sumatera Using Discriminant Analysis

    NASA Astrophysics Data System (ADS)

    Nasution, D. H.; Bangun, P.; Sitepu, H. R.

    2018-04-01

    In Indonesia, especially North Sumatera, the problem of poverty is one of the fundamental problems that become the focus of government both central and local government. Although the poverty rate decreased but the fact is there are many people who are poor. Poverty happens covers several aspects such as education, health, demographics, and also structural and cultural. This research will discuss about several factors such as population density, Unemployment Rate, GDP per capita ADHK, ADHB GDP per capita, economic growth and life expectancy that affect poverty in Indonesia. To determine the factors that most influence and differentiate the level of poverty of the Regency/City North Sumatra used discriminant analysis method. Discriminant analysis is one multivariate analysis technique are used to classify the data into a group based on the dependent variable and independent variable. Using discriminant analysis, it is evident that the factor affecting poverty is Unemployment Rate.

  8. What Is Rotating in Exploratory Factor Analysis?

    ERIC Educational Resources Information Center

    Osborne, Jason W.

    2015-01-01

    Exploratory factor analysis (EFA) is one of the most commonly-reported quantitative methodology in the social sciences, yet much of the detail regarding what happens during an EFA remains unclear. The goal of this brief technical note is to explore what "rotation" is, what exactly is rotating, and why we use rotation when performing…

  9. Logistic Regression and Path Analysis Method to Analyze Factors influencing Students’ Achievement

    NASA Astrophysics Data System (ADS)

    Noeryanti, N.; Suryowati, K.; Setyawan, Y.; Aulia, R. R.

    2018-04-01

    Students' academic achievement cannot be separated from the influence of two factors namely internal and external factors. The first factors of the student (internal factors) consist of intelligence (X1), health (X2), interest (X3), and motivation of students (X4). The external factors consist of family environment (X5), school environment (X6), and society environment (X7). The objects of this research are eighth grade students of the school year 2016/2017 at SMPN 1 Jiwan Madiun sampled by using simple random sampling. Primary data are obtained by distributing questionnaires. The method used in this study is binary logistic regression analysis that aims to identify internal and external factors that affect student’s achievement and how the trends of them. Path Analysis was used to determine the factors that influence directly, indirectly or totally on student’s achievement. Based on the results of binary logistic regression, variables that affect student’s achievement are interest and motivation. And based on the results obtained by path analysis, factors that have a direct impact on student’s achievement are students’ interest (59%) and students’ motivation (27%). While the factors that have indirect influences on students’ achievement, are family environment (97%) and school environment (37).

  10. Confirmatory Factor Analysis of the Delirium Rating Scale Revised-98 (DRS-R98).

    PubMed

    Thurber, Steven; Kishi, Yasuhiro; Trzepacz, Paula T; Franco, Jose G; Meagher, David J; Lee, Yanghyun; Kim, Jeong-Lan; Furlanetto, Leticia M; Negreiros, Daniel; Huang, Ming-Chyi; Chen, Chun-Hsin; Kean, Jacob; Leonard, Maeve

    2015-01-01

    Principal components analysis applied to the Delirium Rating Scale-Revised-98 contributes to understanding the delirium construct. Using a multisite pooled international delirium database, the authors applied confirmatory factor analysis to Delirium Rating Scale-Revised-98 scores from 859 adult patients evaluated by delirium experts (delirium, N=516; nondelirium, N=343). Confirmatory factor analysis found all diagnostic features and core symptoms (cognitive, language, thought process, sleep-wake cycle, motor retardation), except motor agitation, loaded onto factor 1. Motor agitation loaded onto factor 2 with noncore symptoms (delusions, affective lability, and perceptual disturbances). Factor 1 loading supports delirium as a single construct, but when accompanied by psychosis, motor agitation's role may not be solely as a circadian activity indicator.

  11. Factor Analysis of the Aberrant Behavior Checklist in Individuals with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Brinkley, Jason; Nations, Laura; Abramson, Ruth K.; Hall, Alicia; Wright, Harry H.; Gabriels, Robin; Gilbert, John R.; Pericak-Vance, Margaret A. O.; Cuccaro, Michael L.

    2007-01-01

    Exploratory factor analysis (varimax and promax rotations) of the aberrant behavior checklist-community version (ABC) in 275 individuals with Autism spectrum disorder (ASD) identified four- and five-factor solutions which accounted for greater than 70% of the variance. Confirmatory factor analysis (Lisrel 8.7) revealed indices of moderate fit for…

  12. A factor analysis of landscape pattern and structure metrics

    Treesearch

    Kurt H. Riitters; R.V. O' Neill; C.T. Hunsaker; James D. Wickham; D.H. Yankee; S.P. Timmins; K.B. Jones; B.L. Jackson

    1995-01-01

    Fifty-five metrics of landscape pattern and structure were calculated for 85 maps of land use and land cover. A multivariate factor analysis was used to identify the common axes (or dimensions) of pattern and structure which were measured by a reduced set of 26 metrics. The first six factors explained about 87% of the variation in the 26 landscape metrics. These...

  13. Phenotypic factor analysis of psychopathology reveals a new body-related transdiagnostic factor.

    PubMed

    Pezzoli, Patrizia; Antfolk, Jan; Santtila, Pekka

    2017-01-01

    Comorbidity challenges the notion of mental disorders as discrete categories. An increasing body of literature shows that symptoms cut across traditional diagnostic boundaries and interact in shaping the latent structure of psychopathology. Using exploratory and confirmatory factor analysis, we reveal the latent sources of covariation among nine measures of psychopathological functioning in a population-based sample of 13024 Finnish twins and their siblings. By implementing unidimensional, multidimensional, second-order, and bifactor models, we illustrate the relationships between observed variables, specific, and general latent factors. We also provide the first investigation to date of measurement invariance of the bifactor model of psychopathology across gender and age groups. Our main result is the identification of a distinct "Body" factor, alongside the previously identified Internalizing and Externalizing factors. We also report relevant cross-disorder associations, especially between body-related psychopathology and trait anger, as well as substantial sex and age differences in observed and latent means. The findings expand the meta-structure of psychopathology, with implications for empirical and clinical practice, and demonstrate shared mechanisms underlying attitudes towards nutrition, self-image, sexuality and anger, with gender- and age-specific features.

  14. Bayes factor design analysis: Planning for compelling evidence.

    PubMed

    Schönbrodt, Felix D; Wagenmakers, Eric-Jan

    2018-02-01

    A sizeable literature exists on the use of frequentist power analysis in the null-hypothesis significance testing (NHST) paradigm to facilitate the design of informative experiments. In contrast, there is almost no literature that discusses the design of experiments when Bayes factors (BFs) are used as a measure of evidence. Here we explore Bayes Factor Design Analysis (BFDA) as a useful tool to design studies for maximum efficiency and informativeness. We elaborate on three possible BF designs, (a) a fixed-n design, (b) an open-ended Sequential Bayes Factor (SBF) design, where researchers can test after each participant and can stop data collection whenever there is strong evidence for either [Formula: see text] or [Formula: see text], and (c) a modified SBF design that defines a maximal sample size where data collection is stopped regardless of the current state of evidence. We demonstrate how the properties of each design (i.e., expected strength of evidence, expected sample size, expected probability of misleading evidence, expected probability of weak evidence) can be evaluated using Monte Carlo simulations and equip researchers with the necessary information to compute their own Bayesian design analyses.

  15. Application of the Bootstrap Methods in Factor Analysis.

    ERIC Educational Resources Information Center

    Ichikawa, Masanori; Konishi, Sadanori

    1995-01-01

    A Monte Carlo experiment was conducted to investigate the performance of bootstrap methods in normal theory maximum likelihood factor analysis when the distributional assumption was satisfied or unsatisfied. Problems arising with the use of bootstrap methods are highlighted. (SLD)

  16. Exploratory Factor Analysis with Small Sample Sizes

    ERIC Educational Resources Information Center

    de Winter, J. C. F.; Dodou, D.; Wieringa, P. A.

    2009-01-01

    Exploratory factor analysis (EFA) is generally regarded as a technique for large sample sizes ("N"), with N = 50 as a reasonable absolute minimum. This study offers a comprehensive overview of the conditions in which EFA can yield good quality results for "N" below 50. Simulations were carried out to estimate the minimum required "N" for different…

  17. Space Human Factors Engineering Gap Analysis Project Final Report

    NASA Technical Reports Server (NTRS)

    Hudy, Cynthia; Woolford, Barbara

    2006-01-01

    Humans perform critical functions throughout each phase of every space mission, beginning with the mission concept and continuing to post-mission analysis (Life Sciences Division, 1996). Space missions present humans with many challenges - the microgravity environment, relative isolation, and inherent dangers of the mission all present unique issues. As mission duration and distance from Earth increases, in-flight crew autonomy will increase along with increased complexity. As efforts for exploring the moon and Mars advance, there is a need for space human factors research and technology development to play a significant role in both on-orbit human-system interaction, as well as the development of mission requirements and needs before and after the mission. As part of the Space Human Factors Engineering (SHFE) Project within the Human Research Program (HRP), a six-month Gap Analysis Project (GAP) was funded to identify any human factors research gaps or knowledge needs. The overall aim of the project was to review the current state of human factors topic areas and requirements to determine what data, processes, or tools are needed to aid in the planning and development of future exploration missions, and also to prioritize proposals for future research and technology development.

  18. Assessing Suicide Risk Among Callers to Crisis Hotlines: A Confirmatory Factor Analysis

    PubMed Central

    Witte, Tracy K.; Gould, Madelyn S.; Munfakh, Jimmie Lou Harris; Kleinman, Marjorie; Joiner, Thomas E.; Kalafat, John

    2012-01-01

    Our goal was to investigate the factor structure of a risk assessment tool utilized by suicide hotlines and to determine the predictive validity of the obtained factors in predicting subsequent suicidal behavior. 1,085 suicidal callers to crisis hotlines were divided into three sub-samples, which allowed us to conduct an independent Exploratory Factor Analysis (EFA), EFA in a Confirmatory Factor Analysis (EFA/CFA) framework, and CFA. Similar to previous factor analytic studies (Beck et al., 1997; Holden & DeLisle, 2005; Joiner, Rudd, & Rajab, 1997; Witte et al., 2006), we found consistent evidence for a two-factor solution, with one factor representing a more pernicious form of suicide risk (i.e., Resolved Plans and Preparations) and one factor representing more mild suicidal ideation (i.e., Suicidal Desire and Ideation). Using structural equation modeling techniques, we found preliminary evidence that the Resolved Plans and Preparations factor trended toward being more predictive of suicidal ideation than the Suicidal Desire and Ideation factor. This factor analytic study is the first longitudinal study of the obtained factors. PMID:20578186

  19. Advanced Composite Wind Turbine Blade Design Based on Durability and Damage Tolerance

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

    Abumeri, Galib; Abdi, Frank

    2012-02-16

    The objective of the program was to demonstrate and verify Certification-by-Analysis (CBA) capability for wind turbine blades made from advanced lightweight composite materials. The approach integrated durability and damage tolerance analysis with robust design and virtual testing capabilities to deliver superior, durable, low weight, low cost, long life, and reliable wind blade design. The GENOA durability and life prediction software suite was be used as the primary simulation tool. First, a micromechanics-based computational approach was used to assess the durability of composite laminates with ply drop features commonly used in wind turbine applications. Ply drops occur in composite joints andmore » closures of wind turbine blades to reduce skin thicknesses along the blade span. They increase localized stress concentration, which may cause premature delamination failure in composite and reduced fatigue service life. Durability and damage tolerance (D&DT) were evaluated utilizing a multi-scale micro-macro progressive failure analysis (PFA) technique. PFA is finite element based and is capable of detecting all stages of material damage including initiation and propagation of delamination. It assesses multiple failure criteria and includes the effects of manufacturing anomalies (i.e., void, fiber waviness). Two different approaches have been used within PFA. The first approach is Virtual Crack Closure Technique (VCCT) PFA while the second one is strength-based. Constituent stiffness and strength properties for glass and carbon based material systems were reverse engineered for use in D&DT evaluation of coupons with ply drops under static loading. Lamina and laminate properties calculated using manufacturing and composite architecture details matched closely published test data. Similarly, resin properties were determined for fatigue life calculation. The simulation not only reproduced static strength and fatigue life as observed in the test, it also showed

  20. Factor analysis of some socio-economic and demographic variables for Bangladesh.

    PubMed

    Islam, S M

    1986-01-01

    The author carries out an exploratory factor analysis of some socioeconomic and demographic variables for Bangladesh using the classical or common factor approach with the varimax rotation method. The socioeconomic and demographic indicators used in this study include literacy, rate of growth, female employment, economic development, urbanization, population density, childlessness, sex ratio, proportion of women ever married, and fertility. The 18 administrative districts of Bangladesh constitute the unit of analysis. 3 common factors--modernization, fertility, and social progress--are identified in this study to explain the correlations among the set of selected socioeconomic and demographic variables.

  1. Identifying items to assess methodological quality in physical therapy trials: a factor analysis.

    PubMed

    Armijo-Olivo, Susan; Cummings, Greta G; Fuentes, Jorge; Saltaji, Humam; Ha, Christine; Chisholm, Annabritt; Pasichnyk, Dion; Rogers, Todd

    2014-09-01

    Numerous tools and individual items have been proposed to assess the methodological quality of randomized controlled trials (RCTs). The frequency of use of these items varies according to health area, which suggests a lack of agreement regarding their relevance to trial quality or risk of bias. The objectives of this study were: (1) to identify the underlying component structure of items and (2) to determine relevant items to evaluate the quality and risk of bias of trials in physical therapy by using an exploratory factor analysis (EFA). A methodological research design was used, and an EFA was performed. Randomized controlled trials used for this study were randomly selected from searches of the Cochrane Database of Systematic Reviews. Two reviewers used 45 items gathered from 7 different quality tools to assess the methodological quality of the RCTs. An exploratory factor analysis was conducted using the principal axis factoring (PAF) method followed by varimax rotation. Principal axis factoring identified 34 items loaded on 9 common factors: (1) selection bias; (2) performance and detection bias; (3) eligibility, intervention details, and description of outcome measures; (4) psychometric properties of the main outcome; (5) contamination and adherence to treatment; (6) attrition bias; (7) data analysis; (8) sample size; and (9) control and placebo adequacy. Because of the exploratory nature of the results, a confirmatory factor analysis is needed to validate this model. To the authors' knowledge, this is the first factor analysis to explore the underlying component items used to evaluate the methodological quality or risk of bias of RCTs in physical therapy. The items and factors represent a starting point for evaluating the methodological quality and risk of bias in physical therapy trials. Empirical evidence of the association among these items with treatment effects and a confirmatory factor analysis of these results are needed to validate these items.

  2. Bayesian Factor Analysis as a Variable Selection Problem: Alternative Priors and Consequences

    PubMed Central

    Lu, Zhao-Hua; Chow, Sy-Miin; Loken, Eric

    2016-01-01

    Factor analysis is a popular statistical technique for multivariate data analysis. Developments in the structural equation modeling framework have enabled the use of hybrid confirmatory/exploratory approaches in which factor loading structures can be explored relatively flexibly within a confirmatory factor analysis (CFA) framework. Recently, a Bayesian structural equation modeling (BSEM) approach (Muthén & Asparouhov, 2012) has been proposed as a way to explore the presence of cross-loadings in CFA models. We show that the issue of determining factor loading patterns may be formulated as a Bayesian variable selection problem in which Muthén and Asparouhov’s approach can be regarded as a BSEM approach with ridge regression prior (BSEM-RP). We propose another Bayesian approach, denoted herein as the Bayesian structural equation modeling with spike and slab prior (BSEM-SSP), which serves as a one-stage alternative to the BSEM-RP. We review the theoretical advantages and disadvantages of both approaches and compare their empirical performance relative to two modification indices-based approaches and exploratory factor analysis with target rotation. A teacher stress scale data set (Byrne, 2012; Pettegrew & Wolf, 1982) is used to demonstrate our approach. PMID:27314566

  3. Geothermal Play-Fairway Analysis of the Tatun Volcano Group, Taiwan

    NASA Astrophysics Data System (ADS)

    Chen, Yan-Ru; Song, Sheng-Rong

    2017-04-01

    Geothermal energy is a sustainable and low-emission energy resource. It has the advantage of low-cost and withstanding nature hazards. Taiwan is located on the western Ring of Fire and characteristic of widespread hot spring and high surface heat flows, especially on the north of Taiwan. Many previous studies reveal that the Tatun Volcano Group (TVG) has great potential to develop the geothermal energy. However, investment in geothermal development has inherent risk and how to reduce the exploration risk is the most important. The exploration risk can be lowered by using the play-fairway analysis (PFA) that integrates existing data representing the composite risk segments in the region in order to define the exploration strategy. As a result, this study has adapted this logic for geothermal exploration in TVG. There are two necessary factors in geothermal energy, heat and permeability. They are the composite risk segments for geothermal play-fairway analysis. This study analyzes existing geologic, geophysical and geochemical data to construct the heat and permeability potential models. Heat potential model is based on temperature gradient, temperature of hot spring, proximity to hot spring, hydrothermal alteration zones, helium isotope ratios, and magnetics. Permeability potential model is based on fault zone, minor fault, and micro-earthquake activities. Then, these two potential models are weighted by using the Analytical Hierarchy Process (AHP) and combined to rank geothermal favorability. Uncertainty model is occurred by the quality of data and spatial accuracy of data. The goal is to combine the potential model with the uncertainty model as a risk map to find the best drilling site for geothermal exploration in TVG. Integrated results indicate where geothermal potential is the highest and provide the best information for those who want to develop the geothermal exploration in TVG.

  4. Confirmatory Factor Analysis of the Cancer Locus of Control Scale.

    ERIC Educational Resources Information Center

    Henderson, Jessica W.; Donatelle, Rebecca J.; Acock, Alan C.

    2002-01-01

    Conducted a confirmatory factor analysis of the Cancer Locus of Control scale (M. Watson and others, 1990), administered to 543 women with a history of breast cancer. Results support a three-factor model of the scale and support use of the scale to assess control dimensions. (SLD)

  5. Development of a Physiologically Based Pharmacokinetic Model for the Anesthetics Halothane, Isoflurane, and Desflurane in the Pig (SUS SCROFA)

    DTIC Science & Technology

    1999-08-01

    Funding for the work was provided in part by Dr. Harry Salem , SBCCOM/ECBC, Aberdeen Proving Grounds, Maryland. The research described in this report... PFA ) " CA Figure I - Physiologicallly Based Pharmacokinetic Model of the Pig (Sus scrofa). Abbreviations: CA, arterial concentration; CX, exhaled...order metabol. rate constant (/hr-1 kg)’ CONSTANT PLA=3.29 $ ’Liver/air partition coefficient’ CONSTANT PFA =70.27 $ ’Fat/air partition coefficient

  6. Conference on Aerospace Transparent Materials and Enclosures, 18-21 November 1975, Atlanta, Georgia

    DTIC Science & Technology

    1976-04-01

    rapid by stress-assisted sorption . Whatever the mechanism of solvent penetration, the transmission of solvent to the craze tip is governed by fluid flow...420 e. Newer Fluoropolymers: Tefzel. Halar, PFA Because of the recent commercial introduction of these plasti ns, little weathering information is...film in Arizona (reference 33). PFA (perfluoroalkoxy resin) is said to have excellent weather- ability (reference 78). It seems likely that all these

  7. X-ray Photoelectron Spectroscopy Study of Argon-Plasma-Treated Fluoropolymers

    NASA Technical Reports Server (NTRS)

    Golub, Morton A.; Lopata, Eugene S.; Finney, Lorie S.

    1994-01-01

    Films of poly(tetrafluoroethylene) (PTFE) and of a tetrafluoroethylene-perfluoroalkyl vinyl ether (approximately 49:1) copolymer (PFA) were exposed to a radio-frequency argon plasma and then examined by X-ray photoelectron spectroscopy (XPS). The use of fluoropolymer films nearly free of surface hydrocarbon contamination as well as the use of a monochromatized X-ray source for XPS removed two factors contributing to conflicting reports on the effect of exposure time on the fluorine-to-carbon (F/C) and oxygen-to-carbon (O/C) ratios for several Ar-plasma-treated fluoropolymers. Contrary to literature indications, a common pattern was found for PTFE and PFA: a moderate decrease in F/C ratio (from 1.99 to 1.40, and from 1.97 to 1.57, respectively), together with a moderate increase in O/C ratio (from negligible to about 0.10, and from 0.012 to about O.10, respectively) at very short exposures, after which the F/C ratios remained essentially constant on prolonged exposures, while the O/C ratios for PTFE and PFA leveled off at 0.11 and 0.15, respectively. The XPS C(sub 1s), spectra for these polymers exposed to the Ar plasma for 20 min were similar and presented, besides a prominent peak at 292.0 eV (CF2,) and a minor peak at 294.0 or 294.1 eV (CF3), a composite band of four curve-resolved peaks (approximately 285-290 eV) representing various CH, CC, CO, CN, and CF functionalities.

  8. Analysis of Social Cohesion in Health Data by Factor Analysis Method: The Ghanaian Perspective

    ERIC Educational Resources Information Center

    Saeed, Bashiru I. I.; Xicang, Zhao; Musah, A. A. I.; Abdul-Aziz, A. R.; Yawson, Alfred; Karim, Azumah

    2013-01-01

    We investigated the study of the overall social cohesion of Ghanaians. In this study, we considered the paramount interest of the involvement of Ghanaians in their communities, their views of other people and institutions, and their level of interest in both local and national politics. The factor analysis method was employed for analysis using R…

  9. Evidence Regarding the Internal Structure: Confirmatory Factor Analysis

    ERIC Educational Resources Information Center

    Lewis, Todd F.

    2017-01-01

    American Educational Research Association (AERA) standards stipulate that researchers show evidence of the internal structure of instruments. Confirmatory factor analysis (CFA) is one structural equation modeling procedure designed to assess construct validity of assessments that has broad applicability for counselors interested in instrument…

  10. Factor Structure of the Student-Teacher Relationship Scale for Norwegian School-Age Children Explored with Confirmatory Factor Analysis

    ERIC Educational Resources Information Center

    Drugli, May Britt; Hjemdal, Odin

    2013-01-01

    The validity of the Student-Teacher Relationship Scale (STRS) was examined in a national sample of 863 Norwegian schoolchildren in grades 1-7 (aged 6-13). The original factor structure of the STRS was tested by confirmatory factor analysis (CFA). The CFA results did not support the original three-factor structure of the STRS. Subsequent CFA of the…

  11. The School Counselor Leadership Survey: Instrument Development and Exploratory Factor Analysis

    ERIC Educational Resources Information Center

    Young, Anita; Bryan, Julia

    2015-01-01

    This study examined the factor structure of the School Counselor Leadership Survey (SCLS). Survey development was a threefold process that resulted in a 39-item survey of 801 school counselors and school counselor supervisors. The exploratory factor analysis indicated a five-factor structure that revealed five key dimensions of school counselor…

  12. Determinants of Standard Errors of MLEs in Confirmatory Factor Analysis

    ERIC Educational Resources Information Center

    Yuan, Ke-Hai; Cheng, Ying; Zhang, Wei

    2010-01-01

    This paper studies changes of standard errors (SE) of the normal-distribution-based maximum likelihood estimates (MLE) for confirmatory factor models as model parameters vary. Using logical analysis, simplified formulas and numerical verification, monotonic relationships between SEs and factor loadings as well as unique variances are found.…

  13. A Primer on Bootstrap Factor Analysis as Applied to Health Studies Research

    ERIC Educational Resources Information Center

    Lu, Wenhua; Miao, Jingang; McKyer, E. Lisako J.

    2014-01-01

    Objectives: To demonstrate how the bootstrap method could be conducted in exploratory factor analysis (EFA) with a syntax written in SPSS. Methods: The data obtained from the Texas Childhood Obesity Prevention Policy Evaluation project (T-COPPE project) were used for illustration. A 5-step procedure to conduct bootstrap factor analysis (BFA) was…

  14. A Caltech MURI Center for Quantum Networks

    DTIC Science & Technology

    2006-05-31

    the code. Thus the dimension of the code space is n5uPfAu5detD , ~64! where PfA denotes the Pfaffian, the square root of the deter- minant of the...material properties, such as bulk ab- sorption and surface scattering. However, as one moves to very small spheres with radius a&10 mm, the intrinsic...1550 nm, which yields a quality factor of Qbulk;3.8310 11. The quality factor due to surface scattering Qs.s. and ab- sorption by adsorbed water Qw has

  15. Utility of adenosine deaminase (ADA), PCR & thoracoscopy in differentiating tuberculous & non-tuberculous pleural effusion complicating chronic kidney disease.

    PubMed

    Kumar, Sravan; Agarwal, Ritesh; Bal, Amanjit; Sharma, Kusum; Singh, Navneet; Aggarwal, Ashutosh N; Verma, Indu; Rana, Satyawati V; Jha, Vivekanand

    2015-03-01

    Pleural effusion is a common occurrence in patients with late-stage chronic kidney disease (CKD). In developing countries, many effusions remain undiagnosed after pleural fluid analysis (PFA) and patients are empirically treated with antitubercular therapy. The aim of this study was to evaluate the role of adenosine deaminase (ADA), nucleic acid amplification tests (NAAT) and medical thoracoscopy in distinguishing tubercular and non-tubercular aetiologies in exudative pleural effusions complicating CKD. Consecutive stage 4 and 5 CKD patients with pleural effusions underwent PFA including ADA and PCR [65 kDa gene; multiplex (IS6110, protein antigen b, MPB64)]. Patients with exudative pleural effusion undiagnosed after PFA underwent medical thoracoscopy. All 107 patients underwent thoracocentesis with 45 and 62 patients diagnosed as transudative and exudative pleural effusions, respectively. Twenty six of the 62 patients underwent medical thoracoscopy. Tuberculous pleurisy was diagnosed in six while uraemic pleuritis was diagnosed in 20 subjects. The sensitivity and specificity of pleural fluid ADA, 65 kDa gene PCR, and multiplex PCR were 66.7 and 90 per cent, 100 and 50 per cent, and 100 and 100 per cent, respectively. Thoracoscopy was associated with five complications in three patients. Uraemia remains the most common cause of pleural effusion in CKD even in high TB prevalence country. Multiplex PCR and thoracoscopy are useful investigations in the diagnostic work-up of pleural effusions complicating CKD while the sensitivity and/or specificity of ADA and 65 kDa gene PCR is poor.

  16. AIS spectra of desert shrub canopies

    NASA Technical Reports Server (NTRS)

    Murray, R.; Isaacson, D. L.; Schrumpf, B. J.; Ripple, W. J.; Lewis, A. J.

    1986-01-01

    Airborne Imaging Spectrometer (AIS) data were collected 30 August 1985 from a desert shrub community in central Oregon. Spectra from artificial targets placed on the test site and from bare soil, big sagebrush (Artemesia tridentata wyomingensis), silver sagebrush (Artemesia cana bolander), and exposed volcanic rocks were studied. Spectral data from grating position 3 (tree mode) were selected from 25 ground positions for analysis by Principal Factor Analysis (PFA). In this grating position, as many as six factors were identified as significant in contributing to spectral structure. Channels 74 through 84 (tree mode) best characterized between-class differences. Other channels were identified as nondiscriminating and as associated with such errors as excessive atmospheric absorption and grating positin changes. The test site was relatively simple with the two species (A. tridentata and A. cana) representing nearly 95% of biomass and with only two mineral backgrounds, a montmorillonitic soil and volcanic rocks. If, as in this study, six factors of spectral structure can be extracted from a single grating position from data acquired over a simple vegetation community, then AIS data must be considered rich in information-gathering potential.

  17. Understanding Older Adults' Perceptions of Internet Use: An Exploratory Factor Analysis

    ERIC Educational Resources Information Center

    Zheng, Robert; Spears, Jeffrey; Luptak, Marilyn; Wilby, Frances

    2015-01-01

    The current study examined factors related to older adults' perceptions of Internet use. Three hundred ninety five older adults participated in the study. The factor analysis revealed four factors perceived by older adults as critical to their Internet use: social connection, self-efficacy, the need to seek financial information, and the need to…

  18. Factor analysis and multiple regression between topography and precipitation on Jeju Island, Korea

    NASA Astrophysics Data System (ADS)

    Um, Myoung-Jin; Yun, Hyeseon; Jeong, Chang-Sam; Heo, Jun-Haeng

    2011-11-01

    SummaryIn this study, new factors that influence precipitation were extracted from geographic variables using factor analysis, which allow for an accurate estimation of orographic precipitation. Correlation analysis was also used to examine the relationship between nine topographic variables from digital elevation models (DEMs) and the precipitation in Jeju Island. In addition, a spatial analysis was performed in order to verify the validity of the regression model. From the results of the correlation analysis, it was found that all of the topographic variables had a positive correlation with the precipitation. The relations between the variables also changed in accordance with a change in the precipitation duration. However, upon examining the correlation matrix, no significant relationship between the latitude and the aspect was found. According to the factor analysis, eight topographic variables (latitude being the exception) were found to have a direct influence on the precipitation. Three factors were then extracted from the eight topographic variables. By directly comparing the multiple regression model with the factors (model 1) to the multiple regression model with the topographic variables (model 3), it was found that model 1 did not violate the limits of statistical significance and multicollinearity. As such, model 1 was considered to be appropriate for estimating the precipitation when taking into account the topography. In the study of model 1, the multiple regression model using factor analysis was found to be the best method for estimating the orographic precipitation on Jeju Island.

  19. Objective Analysis of Oceanic Data for Coast Guard Trajectory Models Phase II

    DTIC Science & Technology

    1997-12-01

    as outliers depends on the desired probability of false alarm, Pfa values, which is the probability of marking a valid point as an outlier. Table 2-2...constructed to minimize the mean-squared prediction error of the grid point estimate under the constraint that the estimate is unbiased . The...prediction error, e= Zl(S) _oizl(Si)+oC1iZz(S) (2.44) subject to the constraints of unbiasedness , • c/1 = 1,and (2.45) i SCC12 = 0. (2.46) Denoting

  20. Leptin receptor neurons in the mouse hypothalamus are colocalized with the neuropeptide galanin and mediate anorexigenic leptin action

    PubMed Central

    Laque, Amanda; Zhang, Yan; Gettys, Sarah; Nguyen, Tu-Anh; Bui, Kelly; Morrison, Christopher D.

    2013-01-01

    Leptin acts centrally via leptin receptor (LepRb)-expressing neurons to regulate food intake, energy expenditure, and other physiological functions. LepRb neurons are found throughout the brain, and several distinct populations contribute to energy homeostasis control. However, the function of most LepRb populations remains unknown, and their contribution to regulate energy homeostasis has not been studied. Galanin has been hypothesized to interact with the leptin signaling system, but literature investigating colocalization of LepRb and galanin has been inconsistent, which is likely due to technical difficulties to visualize both. We used reporter mice with green fluorescent protein expression from the galanin locus to recapitulate the colocalization of galanin and leptin-induced p-STAT3 as a marker for LepRb expression. Here, we report the existence of two populations of galanin-expressing LepRb neurons (Gal-LepRb neurons): in the hypothalamus overspanning the perifornical area and adjacent dorsomedial and lateral hypothalamus [collectively named extended perifornical area (exPFA)] and in the brainstem (nucleus of the solitary tract). Surprisingly, despite the known orexigenic galanin action, leptin induces galanin mRNA expression and stimulates LepRb neurons in the exPFA, thus conflicting with the expected anorexigenic leptin action. However, we confirmed that intra-exPFA leptin injections were indeed sufficient to mediate anorexic responses. Interestingly, LepRb and galanin-expressing neurons are distinct from orexin or melanin-concentrating hormone (MCH)-expressing neurons, but exPFA galanin neurons colocalized with the anorexigenic neuropeptides neurotensin and cocaine- and amphetamine-regulated transcript (CART). Based on galanin's known inhibitory function, we speculate that in exPFA Gal-LepRb neurons galanin acts inhibitory rather than orexigenic. PMID:23482448

  1. Confirmatory factor analysis of the Child Oral Health Impact Profile (Korean version).

    PubMed

    Cho, Young Il; Lee, Soonmook; Patton, Lauren L; Kim, Hae-Young

    2016-04-01

    Empirical support for the factor structure of the Child Oral Health Impact Profile (COHIP) has not been fully established. The purposes of this study were to evaluate the factor structure of the Korean version of the COHIP (COHIP-K) empirically using confirmatory factor analysis (CFA) based on the theoretical framework and then to assess whether any of the factors in the structure could be grouped into a simpler single second-order factor. Data were collected through self-reported COHIP-K responses from a representative community sample of 2,236 Korean children, 8-15 yr of age. Because a large inter-factor correlation of 0.92 was estimated in the original five-factor structure, the two strongly correlated factors were combined into one factor, resulting in a four-factor structure. The revised four-factor model showed a reasonable fit with appropriate inter-factor correlations. Additionally, the second-order model with four sub-factors was reasonable with sufficient fit and showed equal fit to the revised four-factor model. A cross-validation procedure confirmed the appropriateness of the findings. Our analysis empirically supported a four-factor structure of COHIP-K, a summarized second-order model, and the use of an integrated summary COHIP score. © 2016 Eur J Oral Sci.

  2. Risk analysis of the thermal sterilization process. Analysis of factors affecting the thermal resistance of microorganisms.

    PubMed

    Akterian, S G; Fernandez, P S; Hendrickx, M E; Tobback, P P; Periago, P M; Martinez, A

    1999-03-01

    A risk analysis was applied to experimental heat resistance data. This analysis is an approach for processing experimental thermobacteriological data in order to study the variability of D and z values of target microorganisms depending on the deviations range of environmental factors, to determine the critical factors and to specify their critical tolerance. This analysis is based on sets of sensitivity functions applied to a specific case of experimental data related to the thermoresistance of Clostridium sporogenes and Bacillus stearothermophilus spores. The effect of the following factors was analyzed: the type of target microorganism; nature of the heating substrate; pH, temperature; type of acid employed and NaCl concentration. The type of target microorganism to be inactivated, the nature of the substrate (reference or real food) and the heating temperature were identified as critical factors, determining about 90% of the alteration of the microbiological risk. The effect of the type of acid used for the acidification of products and the concentration of NaCl can be assumed to be negligible factors for the purposes of engineering calculations. The critical non-uniformity in temperature during thermobacteriological studies was set as 0.5% and the critical tolerances of pH value and NaCl concentration were 5%. These results are related to a specific case study, for that reason their direct generalization is not correct.

  3. Surface cell immobilization within perfluoroalkoxy microchannels

    NASA Astrophysics Data System (ADS)

    Stojkovič, Gorazd; Krivec, Matic; Vesel, Alenka; Marinšek, Marjan; Žnidaršič-Plazl, Polona

    2014-11-01

    Perfluoroalkoxy (PFA) is one of the most promising materials for the fabrication of cheap, solvent resistant and reusable microfluidic chips, which have been recently recognized as effective tools for biocatalytic process development. The application of biocatalysts significantly depends on efficient immobilization of enzymes or cells within the reactor enabling long-term biocatalyst use. Functionalization of PFA microchannels by 3-aminopropyltriethoxysilane (ATPES) and glutaraldehyde was used for rapid preparation of microbioreactors with surface-immobilized cells. X-ray photoelectron spectroscopy and scanning electron microscopy were used to accurately monitor individual treatment steps and to select conditions for cell immobilization. The optimized protocol for Saccharomyces cerevisiae immobilization on PFA microchannel walls comprised ethanol surface pretreatment, 4 h contacting with 10% APTES aqueous solution, 10 min treatment with 1% glutaraldehyde and 20 min contacting with cells in deionized water. The same protocol enabled also immobilization of Escherichia coli, Pseudomonas putida and Bacillus subtilis cells on PFA surface in high densities. Furthermore, the developed procedure has been proved to be very efficient also for surface immobilization of tested cells on other materials that are used for microreactor fabrication, including glass, polystyrene, poly (methyl methacrylate), polycarbonate, and two olefin-based polymers, namely Zeonor® and Topas®.

  4. Chemical factor analysis of skin cancer FTIR-FEW spectroscopic data

    NASA Astrophysics Data System (ADS)

    Bruch, Reinhard F.; Sukuta, Sydney

    2002-03-01

    Chemical Factor Analysis (CFA) algorithms were applied to transform complex Fourier transform infrared fiberoptical evanescent wave (FTIR-FEW) normal and malignant skin tissue spectra into factor spaces for analysis and classification. The factor space approach classified melanoma beyond prior pathological classifications related to specific biochemical alterations to health states in cluster diagrams allowing diagnosis with more biochemical specificity, resolving biochemical component spectra and employing health state eigenvector angular configurations as disease state sensors. This study demonstrated a wealth of new information from in vivo FTIR-FEW spectral tissue data, without extensive a priori information or clinically invasive procedures. In particular, we employed a variety of methods used in CFA to select the rank of spectroscopic data sets of normal benign and cancerous skin tissue. We used the Malinowski indicator function (IND), significance level and F-Tests to rank our data matrices. Normal skin tissue, melanoma and benign tumors were modeled by four, two and seven principal abstract factors, respectively. We also showed that the spectrum of the first eigenvalue was equivalent to the mean spectrum. The graphical depiction of angular disparities between the first abstract factors can be adopted as a new way to characterize and diagnose melanoma cancer.

  5. Old and New Ideas for Data Screening and Assumption Testing for Exploratory and Confirmatory Factor Analysis

    PubMed Central

    Flora, David B.; LaBrish, Cathy; Chalmers, R. Philip

    2011-01-01

    We provide a basic review of the data screening and assumption testing issues relevant to exploratory and confirmatory factor analysis along with practical advice for conducting analyses that are sensitive to these concerns. Historically, factor analysis was developed for explaining the relationships among many continuous test scores, which led to the expression of the common factor model as a multivariate linear regression model with observed, continuous variables serving as dependent variables, and unobserved factors as the independent, explanatory variables. Thus, we begin our paper with a review of the assumptions for the common factor model and data screening issues as they pertain to the factor analysis of continuous observed variables. In particular, we describe how principles from regression diagnostics also apply to factor analysis. Next, because modern applications of factor analysis frequently involve the analysis of the individual items from a single test or questionnaire, an important focus of this paper is the factor analysis of items. Although the traditional linear factor model is well-suited to the analysis of continuously distributed variables, commonly used item types, including Likert-type items, almost always produce dichotomous or ordered categorical variables. We describe how relationships among such items are often not well described by product-moment correlations, which has clear ramifications for the traditional linear factor analysis. An alternative, non-linear factor analysis using polychoric correlations has become more readily available to applied researchers and thus more popular. Consequently, we also review the assumptions and data-screening issues involved in this method. Throughout the paper, we demonstrate these procedures using an historic data set of nine cognitive ability variables. PMID:22403561

  6. Determinants of job stress in chemical process industry: A factor analysis approach.

    PubMed

    Menon, Balagopal G; Praveensal, C J; Madhu, G

    2015-01-01

    Job stress is one of the active research domains in industrial safety research. The job stress can result in accidents and health related issues in workers in chemical process industries. Hence it is important to measure the level of job stress in workers so as to mitigate the same to avoid the worker's safety related problems in the industries. The objective of this study is to determine the job stress factors in the chemical process industry in Kerala state, India. This study also aims to propose a comprehensive model and an instrument framework for measuring job stress levels in the chemical process industries in Kerala, India. The data is collected through a questionnaire survey conducted in chemical process industries in Kerala. The collected data out of 1197 surveys is subjected to principal component and confirmatory factor analysis to develop the job stress factor structure. The factor analysis revealed 8 factors that influence the job stress in process industries. It is also found that the job stress in employees is most influenced by role ambiguity and the least by work environment. The study has developed an instrument framework towards measuring job stress utilizing exploratory factor analysis and structural equation modeling.

  7. NASA ISS Portable Fan Assembly Acoustics

    NASA Technical Reports Server (NTRS)

    Boone, Andrew; Allen, Christopher S.; Hess, Linda F.

    2018-01-01

    The Portable Fan Assembly (PFA) is a variable speed fan that can be used to provide additional ventilation inside International Space Station (ISS) modules as needed for crew comfort or for enhanced mixing of the ISS atmosphere. This fan can also be configured with a Shuttle era lithium hydroxide (LiOH) canister for CO2 removal in confined areas partially of fully isolated from the primary Environmental Control and Life Support System (ECLSS) on ISS which is responsible for CO2 removal. This report documents noise emission levels of the PFA at various speed settings and configurations. It also documents the acoustic attenuation effects realized when circulating air through the PFA inlet and outlet mufflers and when operating in its CO2 removal configuration (CRK) with a LiOH canister (sorbent bed) installed over the fan outlet.

  8. An Empirical Analysis of Factors Affecting Honors Program Completion Rates

    ERIC Educational Resources Information Center

    Savage, Hallie; Raehsler, Rod D.; Fiedor, Joseph

    2014-01-01

    One of the most important issues in any educational environment is identifying factors that promote academic success. A plethora of research on such factors exists across most academic fields, involving a wide range of student demographics, and the definition of student success varies across the range of studies published. The analysis in this…

  9. Factors of Spatial Visualization: An Analysis of the PSVT:R

    ERIC Educational Resources Information Center

    Ernst, Jeremy V.; Willams, Thomas O.; Clark, Aaron C.; Kelly, Daniel P.

    2017-01-01

    The Purdue Spatial Visualization Test: Visualization of Rotations (PVST:R) is among the most commonly used measurement instruments to assess spatial ability among engineering students. Previous analysis that explores the factor structure of the PSVT:R indicates a single-factor measure of the instrument. With this as a basis, this research seeks to…

  10. Multiplication factor versus regression analysis in stature estimation from hand and foot dimensions.

    PubMed

    Krishan, Kewal; Kanchan, Tanuj; Sharma, Abhilasha

    2012-05-01

    Estimation of stature is an important parameter in identification of human remains in forensic examinations. The present study is aimed to compare the reliability and accuracy of stature estimation and to demonstrate the variability in estimated stature and actual stature using multiplication factor and regression analysis methods. The study is based on a sample of 246 subjects (123 males and 123 females) from North India aged between 17 and 20 years. Four anthropometric measurements; hand length, hand breadth, foot length and foot breadth taken on the left side in each subject were included in the study. Stature was measured using standard anthropometric techniques. Multiplication factors were calculated and linear regression models were derived for estimation of stature from hand and foot dimensions. Derived multiplication factors and regression formula were applied to the hand and foot measurements in the study sample. The estimated stature from the multiplication factors and regression analysis was compared with the actual stature to find the error in estimated stature. The results indicate that the range of error in estimation of stature from regression analysis method is less than that of multiplication factor method thus, confirming that the regression analysis method is better than multiplication factor analysis in stature estimation. Copyright © 2012 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  11. The risk factors for avian influenza on poultry farms: a meta-analysis.

    PubMed

    Wang, Youming; Li, Peng; Wu, Yangli; Sun, Xiangdong; Yu, Kangzhen; Yu, Chuanhua; Qin, Aijian

    2014-11-01

    Avian influenza is a severe threat both to humans and poultry, but so far, no systematic review on the identification and evaluation of the risk factors of avian influenza infection has been published. The objective of this meta-analysis is to provide evidence for decision-making and further research on AI prevention through identifying the risk factors associated with AI infection on poultry farms. The results from 15 selected studies on risk factors for AI infections on poultry farms were analyzed quantitatively by meta-analysis. Open water source (OR=2.89), infections on nearby farms (OR=4.54), other livestock (OR=1.90) and disinfection of farm (OR=0.54) have significant association with AI infection on poultry farms. The subgroup analysis results indicate that there exist different risk factors for AI infections in different types of farms. The main risk factors for AI infection in poultry farms are environmental conditions (open water source, infections on nearby farms), keeping other livestock on the same farm and no disinfection of the farm. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Identifying Items to Assess Methodological Quality in Physical Therapy Trials: A Factor Analysis

    PubMed Central

    Cummings, Greta G.; Fuentes, Jorge; Saltaji, Humam; Ha, Christine; Chisholm, Annabritt; Pasichnyk, Dion; Rogers, Todd

    2014-01-01

    Background Numerous tools and individual items have been proposed to assess the methodological quality of randomized controlled trials (RCTs). The frequency of use of these items varies according to health area, which suggests a lack of agreement regarding their relevance to trial quality or risk of bias. Objective The objectives of this study were: (1) to identify the underlying component structure of items and (2) to determine relevant items to evaluate the quality and risk of bias of trials in physical therapy by using an exploratory factor analysis (EFA). Design A methodological research design was used, and an EFA was performed. Methods Randomized controlled trials used for this study were randomly selected from searches of the Cochrane Database of Systematic Reviews. Two reviewers used 45 items gathered from 7 different quality tools to assess the methodological quality of the RCTs. An exploratory factor analysis was conducted using the principal axis factoring (PAF) method followed by varimax rotation. Results Principal axis factoring identified 34 items loaded on 9 common factors: (1) selection bias; (2) performance and detection bias; (3) eligibility, intervention details, and description of outcome measures; (4) psychometric properties of the main outcome; (5) contamination and adherence to treatment; (6) attrition bias; (7) data analysis; (8) sample size; and (9) control and placebo adequacy. Limitation Because of the exploratory nature of the results, a confirmatory factor analysis is needed to validate this model. Conclusions To the authors' knowledge, this is the first factor analysis to explore the underlying component items used to evaluate the methodological quality or risk of bias of RCTs in physical therapy. The items and factors represent a starting point for evaluating the methodological quality and risk of bias in physical therapy trials. Empirical evidence of the association among these items with treatment effects and a confirmatory factor

  13. Incidence and risk factors of bleeding-related adverse events in patients with chronic lymphocytic leukemia treated with ibrutinib

    PubMed Central

    Lipsky, Andrew H.; Farooqui, Mohammed Z.H.; Tian, Xin; Martyr, Sabrina; Cullinane, Ann M.; Nghiem, Khanh; Sun, Clare; Valdez, Janet; Niemann, Carsten U.; Herman, Sarah E. M.; Saba, Nakhle; Soto, Susan; Marti, Gerald; Uzel, Gulbu; Holland, Steve M.; Lozier, Jay N.; Wiestner, Adrian

    2015-01-01

    Ibrutinib is associated with bleeding-related adverse events of grade ≤2 in severity, and infrequently with grade ≥3 events. To investigate the mechanisms of bleeding and identify patients at risk, we prospectively assessed platelet function and coagulation factors in our investigator-initiated trial of single-agent ibrutinib for chronic lymphocytic leukemia. At a median follow-up of 24 months we recorded grade ≤2 bleeding-related adverse events in 55% of 85 patients. No grade ≥3 events occurred. Median time to event was 49 days. The cumulative incidence of an event plateaued by 6 months, suggesting that the risk of bleeding decreases with continued therapy. At baseline, von Willebrand factor and factor VIII levels were often high and normalized on treatment. Platelet function measured via the platelet function analyzer (PFA-100™) was impaired in 22 patients at baseline and in an additional 19 patients on ibrutinib (often transiently). Collagen and adenosine diphosphate induced platelet aggregation was tested using whole blood aggregometry. Compared to normal controls, response to both agonists was decreased in all patients with chronic lymphocytic leukemia, whether on ibrutinib or not. Compared to untreated chronic lymphocytic leukemia patients, response to collagen showed a mild further decrement on ibrutinib, while response to adenosine diphosphate improved. All parameters associated with a significantly increased risk of bleeding-related events were present at baseline, including prolonged epinephrine closure time (HR 2.74, P=0.012), lower levels of von Willebrand factor activity (HR 2.73, P=0.009) and factor VIII (HR 3.73, P=0.0004). In conclusion, both disease and treatment-related factors influence the risk of bleeding. Patients at greater risk for bleeding of grade ≤2 can be identified by clinical laboratory tests and counseled to avoid aspirin, non-steroidal anti-inflammatory drugs and fish oils. ClinicalTrials.gov identifier NCT01500733 PMID

  14. [Introduction to Exploratory Factor Analysis (EFA)].

    PubMed

    Martínez, Carolina Méndez; Sepúlveda, Martín Alonso Rondón

    2012-03-01

    Exploratory Factor Analysis (EFA) has become one of the most frequently used statistical techniques, especially in the medical and social sciences. Given its popularity, it is essential to understand the basic concepts necessary for its proper application and to take into consideration the main strengths and weaknesses of this technique. To present in a clear and concise manner the main applications of this technique, to determine the basic requirements for its use providing a description step by step of its methodology, and to establish the elements that must be taken into account during its preparation in order to not incur in erroneous results and interpretations. Narrative review. This review identifies the basic concepts and briefly describes the objectives, design, assumptions, and methodology to achieve factor derivation, global adjustment evaluation, and adequate interpretation of results. Copyright © 2012 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  15. Defense Technology Objectives of the Joint Warfighting Science and Technology Plan and the Defense Technology Area Plan.

    DTIC Science & Technology

    1997-01-01

    isolated targets, significantly reduce false alarms ( PFA = 0.01/km2), and recognize force structure (e.g., maneuver battalions). During FY97, a laboratory...probability of false alarm ( Pfa ) of 0.3 at an altitude of 500-1,000 ft and at airspeeds of 60-100 kn is planned. Enhanced COBRA optics-including a...hibiting the desired properties and initiate agent sorption assessments. The FY00 goal is to com- plete performance evaluations of candidate

  16. Removing Parallax-Induced False Changes in Change Detection

    DTIC Science & Technology

    2014-03-27

    viii Figure Page 11 Three hypothetical ROC curves. The probability of detection (PD) is plotted against the probability of false alarm ( PFA ) based on...red and green) approach the value of PD = 1 and PFA = 0, the detector performance is said to improve. . . . . . . . . . . . . . . . 32 12 Possible... sorption are commonly among those with low SNRs as the gases and vapor in the atmosphere between the (airborne) sensor and the ground plane tend to

  17. Investigation on Constrained Matrix Factorization for Hyperspectral Image Analysis

    DTIC Science & Technology

    2005-07-25

    analysis. Keywords: matrix factorization; nonnegative matrix factorization; linear mixture model ; unsupervised linear unmixing; hyperspectral imagery...spatial resolution permits different materials present in the area covered by a single pixel. The linear mixture model says that a pixel reflectance in...in r. In the linear mixture model , r is considered as the linear mixture of m1, m2, …, mP as nMαr += (1) where n is included to account for

  18. Confirmatory Factor Analysis of the Minnesota Nicotine Withdrawal Scale

    PubMed Central

    Toll, Benjamin A.; O’Malley, Stephanie S.; McKee, Sherry A.; Salovey, Peter; Krishnan-Sarin, Suchitra

    2008-01-01

    The authors examined the factor structure of the Minnesota Nicotine Withdrawal Scale (MNWS) using confirmatory factor analysis in clinical research samples of smokers trying to quit (n = 723). Three confirmatory factor analytic models, based on previous research, were tested with each of the 3 study samples at multiple points in time. A unidimensional model including all 8 MNWS items was found to be the best explanation of the data. This model produced fair to good internal consistency estimates. Additionally, these data revealed that craving should be included in the total score of the MNWS. Factor scores derived from this single-factor, 8-item model showed that increases in withdrawal were associated with poor smoking outcome for 2 of the clinical studies. Confirmatory factor analyses of change scores showed that the MNWS symptoms cohere as a syndrome over time. Future investigators should report a total score using all of the items from the MNWS. PMID:17563141

  19. Meta-analysis of the Brief Psychiatric Rating Scale Factor Structure

    ERIC Educational Resources Information Center

    Shafer, Alan

    2005-01-01

    A meta-analysis (N=17,620; k=26) of factor analyses of the Brief Psychiatric Rating Scale (BPRS) was conducted. Analysis of the 12 items from Overall et al.'s (J. E. Overall, L. E. Hollister, & P. Pichot, 1974) 4 subscales found support for his 4 subscales. Analysis of all 18 BPRS items found 4 components similar to those of Overall et al. In a…

  20. A Human Factors Analysis of EVA Time Requirements

    NASA Technical Reports Server (NTRS)

    Pate, Dennis W.

    1997-01-01

    Human Factors Engineering (HFE) is a discipline whose goal is to engineer a safer, more efficient interface between humans and machines. HFE makes use of a wide range of tools and techniques to fulfill this goal. One of these tools is known as motion and time study, a technique used to develop time standards for given tasks. During the summer of 1995, a human factors motion and time study was initiated with the goals of developing a database of EVA task times and developing a method of utilizing the database to predict how long an EVA should take. Initial development relied on the EVA activities performed during the STS-61 (Hubble) mission. The first step of the study was to become familiar with EVA's, the previous task-time studies, and documents produced on EVA's. After reviewing these documents, an initial set of task primitives and task-time modifiers was developed. Data was collected from videotaped footage of two entire STS-61 EVA missions and portions of several others, each with two EVA astronauts. Feedback from the analysis of the data was used to further refine the primitives and modifiers used. The project was continued during the summer of 1996, during which data on human errors was also collected and analyzed. Additional data from the STS-71 mission was also collected. Analysis of variance techniques for categorical data was used to determine which factors may affect the primitive times and how much of an effect they have. Probability distributions for the various task were also generated. Further analysis of the modifiers and interactions is planned.

  1. Detecting Outliers in Factor Analysis Using the Forward Search Algorithm

    ERIC Educational Resources Information Center

    Mavridis, Dimitris; Moustaki, Irini

    2008-01-01

    In this article we extend and implement the forward search algorithm for identifying atypical subjects/observations in factor analysis models. The forward search has been mainly developed for detecting aberrant observations in regression models (Atkinson, 1994) and in multivariate methods such as cluster and discriminant analysis (Atkinson, Riani,…

  2. Quantitative Analysis of Guanine Nucleotide Exchange Factors (GEFs) as Enzymes

    PubMed Central

    Randazzo, Paul A; Jian, Xiaoying; Chen, Pei-Wen; Zhai, Peng; Soubias, Olivier; Northup, John K

    2014-01-01

    The proteins that possess guanine nucleotide exchange factor (GEF) activity, which include about ~800 G protein coupled receptors (GPCRs),1 15 Arf GEFs,2 81 Rho GEFs,3 8 Ras GEFs,4 and others for other families of GTPases,5 catalyze the exchange of GTP for GDP on all regulatory guanine nucleotide binding proteins. Despite their importance as catalysts, relatively few exchange factors (we are aware of only eight for ras superfamily members) have been rigorously characterized kinetically.5–13 In some cases, kinetic analysis has been simplistic leading to erroneous conclusions about mechanism (as discussed in a recent review14). In this paper, we compare two approaches for determining the kinetic properties of exchange factors: (i) examining individual equilibria, and; (ii) analyzing the exchange factors as enzymes. Each approach, when thoughtfully used,14,15 provides important mechanistic information about the exchange factors. The analysis as enzymes is described in further detail. With the focus on the production of the biologically relevant guanine nucleotide binding protein complexed with GTP (G•GTP), we believe it is conceptually simpler to connect the kinetic properties to cellular effects. Further, the experiments are often more tractable than those used to analyze the equilibrium system and, therefore, more widely accessible to scientists interested in the function of exchange factors. PMID:25332840

  3. Practical limitations of single particle ICP-MS in the determination of nanoparticle size distributions and dissolution: case of rare earth oxides.

    PubMed

    Fréchette-Viens, Laurie; Hadioui, Madjid; Wilkinson, Kevin J

    2017-01-15

    The applicability of single particle ICP-MS (SP-ICP-MS) for the analysis of nanoparticle size distributions and the determination of particle numbers was evaluated using the rare earth oxide, La 2 O 3 , as a model particle. The composition of the storage containers, as well as the ICP-MS sample introduction system were found to significantly impact SP-ICP-MS analysis. While La 2 O 3 nanoparticles (La 2 O 3 NP) did not appear to interact strongly with sample containers, adsorptive losses of La 3+ (over 24h) were substantial (>72%) for fluorinated ethylene propylene bottles as opposed to polypropylene (<10%). Furthermore, each part of the sample introduction system (nebulizers made of perfluoroalkoxy alkane (PFA) or glass, PFA capillary tubing, and polyvinyl chloride (PVC) peristaltic pump tubing) contributed to La 3+ adsorptive losses. On the other hand, the presence of natural organic matter in the nanoparticle suspensions led to a decreased adsorptive loss in both the sample containers and the introduction system, suggesting that SP-ICP-MS may nonetheless be appropriate for NP analysis in environmental matrices. Coupling of an ion-exchange resin to the SP-ICP-MS led to more accurate determinations of the La 2 O 3 NP size distributions. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Students' motivation to study dentistry in Malaysia: an analysis using confirmatory factor analysis.

    PubMed

    Musa, Muhd Firdaus Che; Bernabé, Eduardo; Gallagher, Jennifer E

    2015-06-12

    Malaysia has experienced a significant expansion of dental schools over the past decade. Research into students' motivation may inform recruitment and retention of the future dental workforce. The objectives of this study were to explore students' motivation to study dentistry and whether that motivation varied by students' and school characteristics. All 530 final-year students in 11 dental schools (6 public and 5 private) in Malaysia were invited to participate at the end of 2013. The self-administered questionnaire, developed at King's College London, collected information on students' motivation to study dentistry and demographic background. Responses on students' motivation were collected using five-point ordinal scales. Confirmatory factor analysis (CFA) was used to evaluate the underlying structure of students' motivation to study dentistry. Multivariate analysis of variance (MANOVA) was used to compare factor scores for overall motivation and sub-domains by students' and school characteristics. Three hundred and fifty-six final-year students in eight schools (all public and two private) participated in the survey, representing an 83% response rate for these schools and 67% of all final-year students nationally. The majority of participants were 24 years old (47%), female (70%), Malay (56%) and from middle-income families (41%) and public schools (78%). CFA supported a model with five first-order factors (professional job, healthcare and people, academic, careers advising and family and friends) which were linked to a single second-order factor representing overall students' motivation. Academic factors and healthcare and people had the highest standardized factor loadings (0.90 and 0.71, respectively), suggesting they were the main motivation to study dentistry. MANOVA showed that students from private schools had higher scores for healthcare and people than those in public schools whereas Malay students had lower scores for family and friends than those

  5. An Analysis of Selected Factors Influencing Enrollment Patterns.

    ERIC Educational Resources Information Center

    Heck, James

    This report presents an analysis of factors influencing enrollment patterns at Lake City Community College (LCCC; Florida) and recommends ways to increase enrollments at the college. Section I reviews the methods of collecting data for the report, which included interviews with key college personnel, an examination of social indicators such as…

  6. Dynamic Factor Analysis Models with Time-Varying Parameters

    ERIC Educational Resources Information Center

    Chow, Sy-Miin; Zu, Jiyun; Shifren, Kim; Zhang, Guangjian

    2011-01-01

    Dynamic factor analysis models with time-varying parameters offer a valuable tool for evaluating multivariate time series data with time-varying dynamics and/or measurement properties. We use the Dynamic Model of Activation proposed by Zautra and colleagues (Zautra, Potter, & Reich, 1997) as a motivating example to construct a dynamic factor…

  7. Recovery of Weak Factor Loadings When Adding the Mean Structure in Confirmatory Factor Analysis: A Simulation Study

    PubMed Central

    Ximénez, Carmen

    2016-01-01

    This article extends previous research on the recovery of weak factor loadings in confirmatory factor analysis (CFA) by exploring the effects of adding the mean structure. This issue has not been examined in previous research. This study is based on the framework of Yung and Bentler (1999) and aims to examine the conditions that affect the recovery of weak factor loadings when the model includes the mean structure, compared to analyzing the covariance structure alone. A simulation study was conducted in which several constraints were defined for one-, two-, and three-factor models. Results show that adding the mean structure improves the recovery of weak factor loadings and reduces the asymptotic variances for the factor loadings, particularly for the models with a smaller number of factors and a small sample size. Therefore, under certain circumstances, modeling the means should be seriously considered for covariance models containing weak factor loadings. PMID:26779071

  8. Affective Outcomes of Schooling: Full-Information Item Factor Analysis of a Student Questionnaire.

    ERIC Educational Resources Information Center

    Muraki, Eiji; Engelhard, George, Jr.

    Recent developments in dichotomous factor analysis based on multidimensional item response models (Bock and Aitkin, 1981; Muthen, 1978) provide an effective method for exploring the dimensionality of questionnaire items. Implemented in the TESTFACT program, this "full information" item factor analysis accounts not only for the pairwise joint…

  9. A Study of Algorithms for Covariance Structure Analysis with Specific Comparisons Using Factor Analysis.

    ERIC Educational Resources Information Center

    Lee, S. Y.; Jennrich, R. I.

    1979-01-01

    A variety of algorithms for analyzing covariance structures are considered. Additionally, two methods of estimation, maximum likelihood, and weighted least squares are considered. Comparisons are made between these algorithms and factor analysis. (Author/JKS)

  10. An Analysis of Factors that Influence Enlistment Decisions in the U.S. Army

    DTIC Science & Technology

    1998-03-01

    NAVAL POSTGRADUATE SCHOOL Monterey, California CM THESIS AN ANALYSIS OF FACTORS THAT INFLUENCE ENLISTMENT DECISIONS IN THE U.S. ARMY by Young...TITLE AND SUBTITLE : AN ANALYSIS OF FACTORS THAT INFLUENCE ENLISTMENT DECISIONS IN THE U.S. ARMY 6. AUTHOR(S) Oh, Young Yeol 7...200 words) The purpose of this thesis is to analyze factors that influence decisions to enlist in the U.S. Army. This thesis uses 1997 New Recruit

  11. Socioeconomic Status Index to Interpret Inequalities in Child Development

    PubMed Central

    AHMADI DOULABI, Mahbobeh; SAJEDI, Firoozeh; VAMEGHI, Roshanak; MAZAHERI, Mohammad Ali; AKBARZADEH BAGHBAN, Alireza

    2017-01-01

    Objective There have been contradictory findings on the relationship between Socioeconomic Status (SES) and child development although SES is associated with child development outcomes. The present study intended to define the relationship between SES and child development in Tehran kindergartens, Iran. Materials & Methods This cross-sectional survey studied 1036 children aged 36-60 month, in different kindergartens in Tehran City, Iran, in 2014-2015. The principal factor analysis (PFA) model was employed to construct SES indices. The constructed SES variable was employed as an independent variable in logistic regression model to evaluate its role in developmental delay as a dependent variable. Results The relationship between SES and developmental delay was significant at P=0.003. SES proved to have a significant (P<0.05) impact on developmental delay, both as an independent variable and after controlling risk factors. Conclusion There should be more emphasis on developmental monitoring and appropriate intervention programs for children to give them higher chance of having a more productive life. PMID:28698723

  12. Risky Business: Factor Analysis of Survey Data – Assessing the Probability of Incorrect Dimensionalisation

    PubMed Central

    van der Eijk, Cees; Rose, Jonathan

    2015-01-01

    This paper undertakes a systematic assessment of the extent to which factor analysis the correct number of latent dimensions (factors) when applied to ordered-categorical survey items (so-called Likert items). We simulate 2400 data sets of uni-dimensional Likert items that vary systematically over a range of conditions such as the underlying population distribution, the number of items, the level of random error, and characteristics of items and item-sets. Each of these datasets is factor analysed in a variety of ways that are frequently used in the extant literature, or that are recommended in current methodological texts. These include exploratory factor retention heuristics such as Kaiser’s criterion, Parallel Analysis and a non-graphical scree test, and (for exploratory and confirmatory analyses) evaluations of model fit. These analyses are conducted on the basis of Pearson and polychoric correlations. We find that, irrespective of the particular mode of analysis, factor analysis applied to ordered-categorical survey data very often leads to over-dimensionalisation. The magnitude of this risk depends on the specific way in which factor analysis is conducted, the number of items, the properties of the set of items, and the underlying population distribution. The paper concludes with a discussion of the consequences of over-dimensionalisation, and a brief mention of alternative modes of analysis that are much less prone to such problems. PMID:25789992

  13. Teacher's Corner: Examining Identification Issues in Factor Analysis

    ERIC Educational Resources Information Center

    Hayashi, Kentaro; Marcoulides, George A.

    2006-01-01

    One hundred years have passed since the birth of factor analysis, during which time there have been some major developments and extensions to the methodology. Unfortunately, one issue where the widespread accumulation of knowledge has been rather slow concerns identification. This article provides a didactic discussion of the topic in an attempt…

  14. Modular Open-Source Software for Item Factor Analysis

    ERIC Educational Resources Information Center

    Pritikin, Joshua N.; Hunter, Micheal D.; Boker, Steven M.

    2015-01-01

    This article introduces an item factor analysis (IFA) module for "OpenMx," a free, open-source, and modular statistical modeling package that runs within the R programming environment on GNU/Linux, Mac OS X, and Microsoft Windows. The IFA module offers a novel model specification language that is well suited to programmatic generation…

  15. Perception on obesity among university students: A case study using factor analysis

    NASA Astrophysics Data System (ADS)

    Hassan, Suriani; Rahman, Nur Amira Abdol; Ghazali, Khadizah; Ismail, Norlita; Budin, Kamsia

    2014-07-01

    The purpose of this study was to examine the university students' perceptions on obesity and to compare the difference in mean scores factor based on demographic factors. Data was collected randomly using questionnaires. There were 321 university students participated in this study. Descriptive statistics, factor analysis, normality test, independent t test, one-way ANOVA and non-parametric tests were used in this study. Factor analysis results managed to retrieve three new factors namely impact of the health, impact of the physical appearance and personal factors. The study found that Science students have higher awareness and perceptions than Art students on Factor 1, impact of the health towards overweight problems and obesity. The findings of the study showed students, whose family background has obesity problem have higher awareness and perceptions than students' whose family background has no obesity problem on Factor 1, impact of the health towards overweight problems and obesity. The study also found that students' whose father with primary school level had the lowest awareness and perceptions on Factor 2, impact of the physical appearance towards overweight problems and obesity than other students whose father with higher academic level.

  16. Study of risk factors for gastric cancer by populational databases analysis

    PubMed Central

    Ferrari, Fangio; Reis, Marco Antonio Moura

    2013-01-01

    AIM: To study the association between the incidence of gastric cancer and populational exposure to risk/protective factors through an analysis of international databases. METHODS: Open-access global databases concerning the incidence of gastric cancer and its risk/protective factors were identified through an extensive search on the Web. As its distribution was neither normal nor symmetric, the cancer incidence of each country was categorized according to ranges of percentile distribution. The association of each risk/protective factor with exposure was measured between the extreme ranges of the incidence of gastric cancer (under the 25th percentile and above the 75th percentile) by the use of the Mann-Whitney test, considering a significance level of 0.05. RESULTS: A variable amount of data omission was observed among all of the factors under study. A weak or nonexistent correlation between the incidence of gastric cancer and the study variables was shown by a visual analysis of scatterplot dispersion. In contrast, an analysis of categorized incidence revealed that the countries with the highest human development index (HDI) values had the highest rates of obesity in males and the highest consumption of alcohol, tobacco, fruits, vegetables and meat, which were associated with higher incidences of gastric cancer. There was no significant difference for the risk factors of obesity in females and fish consumption. CONCLUSION: Higher HDI values, coupled with a higher prevalence of male obesity and a higher per capita consumption of alcohol, tobacco, fruits, vegetables and meat, are associated with a higher incidence of gastric cancer based on an analysis of populational global data. PMID:24409066

  17. An Evaluation of the Effects of Variable Sampling on Component, Image, and Factor Analysis.

    ERIC Educational Resources Information Center

    Velicer, Wayne F.; Fava, Joseph L.

    1987-01-01

    Principal component analysis, image component analysis, and maximum likelihood factor analysis were compared to assess the effects of variable sampling. Results with respect to degree of saturation and average number of variables per factor were clear and dramatic. Differential effects on boundary cases and nonconvergence problems were also found.…

  18. A factor analysis of the SSQ (Speech, Spatial, and Qualities of Hearing Scale).

    PubMed

    Akeroyd, Michael A; Guy, Fiona H; Harrison, Dawn L; Suller, Sharon L

    2014-02-01

    The speech, spatial, and qualities of hearing questionnaire (SSQ) is a self-report test of auditory disability. The 49 items ask how well a listener would do in many complex listening situations illustrative of real life. The scores on the items are often combined into the three main sections or into 10 pragmatic subscales. We report here a factor analysis of the SSQ that we conducted to further investigate its statistical properties and to determine its structure. Statistical factor analysis of questionnaire data, using parallel analysis to determine the number of factors to retain, oblique rotation of factors, and a bootstrap method to estimate the confidence intervals. 1220 people who have attended MRC IHR over the last decade. We found three clear factors, essentially corresponding to the three main sections of the SSQ. They are termed "speech understanding", "spatial perception", and "clarity, separation, and identification". Thirty-five of the SSQ questions were included in the three factors. There was partial evidence for a fourth factor, "effort and concentration", representing two more questions. These results aid in the interpretation and application of the SSQ and indicate potential methods for generating average scores.

  19. Psychological Factors and Conditioned Pain Modulation: A Meta-Analysis.

    PubMed

    Nahman-Averbuch, Hadas; Nir, Rony-Reuven; Sprecher, Elliot; Yarnitsky, David

    2016-06-01

    Conditioned pain modulation (CPM) responses may be affected by psychological factors such as anxiety, depression, and pain catastrophizing; however, most studies on CPM do not address these relations as their primary outcome. The aim of this meta-analysis was to analyze the findings regarding the associations between CPM responses and psychological factors in both pain-free individuals and pain patients. After a comprehensive PubMed search, 37 articles were found to be suitable for inclusion. Analyses used DerSimonian and Laird's random-effects model on Fisher's z-transforms of correlations; potential publication bias was tested using funnel plots and Egger's regression test for funnel plot asymmetry. Six meta-analyses were performed examining the correlations between anxiety, depression, and pain catastrophizing, and CPM responses in healthy individuals and pain patients. No significant correlations between CPM responses and any of the examined psychological factors were found. However, a secondary analysis, comparing modality-specific CPM responses and psychological factors in healthy individuals, revealed the following: (1) pressure-based CPM responses were correlated with anxiety (grand mean correlation in original units r=-0.1087; 95% confidence limits, -0.1752 to -0.0411); (2) heat-based CPM was correlated with depression (r=0.2443; 95% confidence limits, 0.0150 to 0.4492); and (3) electrical-based CPM was correlated with pain catastrophizing levels (r=-0.1501; 95% confidence limits, -0.2403 to -0.0574). Certain psychological factors seem to be associated with modality-specific CPM responses in healthy individuals. This potentially supports the notion that CPM paradigms evoked by different stimulation modalities represent different underlying mechanisms.

  20. Exploring factors that influence work analysis data: A meta-analysis of design choices, purposes, and organizational context.

    PubMed

    DuVernet, Amy M; Dierdorff, Erich C; Wilson, Mark A

    2015-09-01

    Work analysis is fundamental to designing effective human resource systems. The current investigation extends previous research by identifying the differential effects of common design decisions, purposes, and organizational contexts on the data generated by work analyses. The effects of 19 distinct factors that span choices of descriptor, collection method, rating scale, and data source, as well as project purpose and organizational features, are explored. Meta-analytic results cumulated from 205 articles indicate that many of these variables hold significant consequences for work analysis data. Factors pertaining to descriptor choice, collection method, rating scale, and the purpose for conducting the work analysis each showed strong associations with work analysis data. The source of the work analysis information and organizational context in which it was conducted displayed fewer relationships. Findings can be used to inform choices work analysts make about methodology and postcollection evaluations of work analysis information. (c) 2015 APA, all rights reserved).

  1. A Confirmatory Factor Analysis of the Structure of Abbreviated Math Anxiety Scale

    PubMed Central

    Farrokhi, Farahman

    2011-01-01

    Objective The aim of this study is to explore the confirmatory factor analysis results of the Persian adaptation of Abbreviated Math Anxiety Scale (AMAS), proposed by Hopko, Mahadevan, Bare & Hunt. Method The validity and reliability assessments of the scale were performed on 298 college students chosen randomly from Tabriz University in Iran. The confirmatory factor analysis (CFA) was carried out to determine the factor structures of the Persian version of AMAS. Results As expected, the two-factor solution provided a better fit to the data than a single factor. Moreover, multi-group analyses showed that this two-factor structure was invariant across sex. Hence, AMAS provides an equally valid measure for use among college students. Conclusions Brief AMAS demonstrates adequate reliability and validity. The AMAS scores can be used to compare symptoms of math anxiety between male and female students. The study both expands and adds support to the existing body of math anxiety literature. PMID:22952521

  2. Tissue sparing surgery in knee reconstruction: unicompartmental (UKA), patellofemoral (PFA), UKA + PFA, bi-unicompartmental (Bi-UKA) arthroplasties

    PubMed Central

    Manzotti, A.; Montironi, F.; Pullen, C.

    2008-01-01

    Recently mini-invasive joint replacement has become one of the hottest topics in the orthopaedic world. However, these terms have been improperly misunderstood as a “key-hole” surgery where traditional components are implanted with shorter surgical approaches, with few benefits and several possible dangers. Small implants as unicompartmental knee prostheses, patellofemoral prostheses and bi-unicompartmental knee prostheses might represent real less invasive procedures: Tissue sparing surgery, the Italian way to minimally invasive surgery (MIS). According to their experience the authors go through this real tissue sparing surgery not limited only to a small incision, but where the surgeons can respect the physiological joint biomechanics. PMID:19384616

  3. Evaluation of the Snap Sampler for Sampling Ground Water Monitoring Wells for Inorganic Analytes

    DTIC Science & Technology

    2008-12-01

    08-25 3 Accumulation samplers rely on both diffusion through a membrane and then sorption by some type of sorbent material that is contained in the...the materials in the sampler to equilibrate with the analytes in the well water thereby prevent- ing losses of analytes due to sorption by the sampler...The spring in the bottles is coated with perfluoroalkoxy ( PFA ) (Teflon) and is connected to PFA end caps at both ends of the bottle. Currently

  4. Analysis of risk factors in the development of retinopathy of prematurity.

    PubMed

    Knezević, Sanja; Stojanović, Nadezda; Oros, Ana; Savić, Dragana; Simović, Aleksandra; Knezević, Jasmina

    2011-01-01

    Retinopathy of prematurity (ROP) is a multifactorial disease that occurs most frequently in very small and very sick preterm infants, and it has been identified as the major cause of childhood blindness. The aim of this study was to evaluate ROP incidence and risk factors associated with varying degrees of illness. The study was conducted at the Centre for Neonatology, Paediatric Clinic of the Clinical Centre Kragujevac, Serbia, in the period from June 2006 to December 2008. Ophthalmologic screening was performed in all children with body weight lower than 2000 g or gestational age lower than 36 weeks. We analyzed eighteen postnatal and six perinatal risk factors and the group correlations for each of the risk factors. Out of 317 children that were screened, 56 (17.7%) developed a mild form of ROP, while 68 (21.5%) developed a severe form. Univariate analysis revealed a large number of statistically significant risk factors for the development of ROP, especially the severe form. Multivariate logistical analysis further separated two independent risk factors: small birth weight (p = 0.001) and damage of central nervous system (p = 0.01). Independent risk factors for transition from mild to severe forms of ROP were identified as: small birth weight (p = 0.05) and perinatal risk factors (p = 0.02). Small birth weight and central nervous system damage were risk factors for the development of ROP, perinatal risk factors were identified as significant for transition from mild to severe form of ROP.

  5. Production of high quality brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB) RNA from isolated populations of rat spinal cord motor neurons obtained by Laser Capture Microdissection (LCM).

    PubMed

    Mehta, Prachi; Premkumar, Brian; Morris, Renée

    2016-08-03

    The mammalian central nervous system (CNS) is composed of multiple cellular elements, making it challenging to segregate one particular cell type to study their gene expression profile. For instance, as motor neurons represent only 5-10% of the total cell population of the spinal cord, meaningful transcriptional analysis on these neurons is almost impossible to achieve from homogenized spinal cord tissue. A major challenge faced by scientists is to obtain good quality RNA from small amounts of starting material. In this paper, we used Laser Capture Microdissection (LCM) techniques to identify and isolate spinal cord motor neurons. The present analysis revealed that perfusion with paraformaldehyde (PFA) does not alter RNA quality. RNA integrity numbers (RINs) of tissue samples from rubrospinal tract (RST)-transected, intact spinal cord or from whole spinal cord homogenate were all above 8, which indicates intact, high-quality RNA. Levels of mRNA for brain-derived neurotrophic factor (BDNF) or for its tropomyosin receptor kinase B (TrkB) were not affected by rubrospinal tract (RST) transection, a surgical procedure that deprive motor neurons from one of their main supraspinal input. The isolation of pure populations of neurons with LCM techniques allows for robust transcriptional characterization that cannot be achieved with spinal cord homogenates. Such preparations of pure population of motor neurons will provide valuable tools to advance our understanding of the molecular mechanisms underlying spinal cord injury and neuromuscular diseases. In the near future, LCM techniques might be instrumental to the success of gene therapy for these debilitating conditions. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. The Potential Efficacy of Psychological First Aid on Self-Reported Anxiety and Mood: A Pilot Study.

    PubMed

    Everly, George S; Lating, Jeffrey M; Sherman, Martin F; Goncher, Ian

    2016-03-01

    The authors explored the efficacy of a randomized controlled trial to assess the potential benefits of psychological first aid (PFA) compared with a social acknowledgement condition in a sample of 42 participants who spoke about a stressful life event. Demographics and standardized questionnaires, including the state version of the State Trait Anxiety Inventory Scale and the Brief Profile of Mood States, assessed anxiety and mood state. Those in the PFA group evidenced significantly lower anxiety scores at 30-minute postdisclosure than at baseline and, although not significant, showed lowered distressed mood compared with baseline at 30-minute postdisclosure. Those in the social acknowledgment condition evidenced increases in anxiety and distressed mood scores, albeit not significantly, at 30 minutes post disclosure compared with their baseline scores. These results provide preliminary empirical evidence for the efficacy of PFA, and implications for intervention and additional assessment are suggested.

  7. Correction of Patellofemoral Malalignment With Patellofemoral Arthroplasty.

    PubMed

    Valoroso, Marco; Saffarini, Mo; La Barbera, Giuseppe; Toanen, Cécile; Hannink, Gerjon; Nover, Luca; Dejour, David H

    2017-12-01

    The goal of patellofemoral arthroplasty (PFA) is to replace damaged cartilage and correct underlying deformities to reduce pain and prevent maltracking. We aimed to determine how PFA modifies patellar height, tilt, and tibial tuberosity-trochlear groove (TT-TG) distance. The hypothesis was that PFA would correct trochlear dysplasia or extensor mechanism malalignment. The authors prospectively studied a series of 16 patients (13 women and 3 men) aged 64.9 ± 16.3 years (range 41-86 years) who received PFA. All knees were assessed preoperatively and 6 months postoperatively using frontal, lateral, and "skyline" x-rays, and computed tomography scans to calculate patellar tilt, patellar height, and TT-TG distance. The interobserver agreement was excellent for all parameters (intraclass correlation coefficient >0.95). Preoperatively, the median patellar tilt without quadriceps contraction (QC) was 17.5° (range 5.3°-33.4°) and with QC was 19.8° (range 0°-52.0°). The median Caton-Deschamps index was 0.91 (range 0.80-1.22) and TT-TG distance was 14.5 mm (range 4.0-22.0 mm). Postoperatively, the median patellar tilt without QC was 0.3° (range -15.3° to 9.5°) and with QC was 6.1° (range -11.5° to 13.3°). The median Caton-Deschamps index was 1.11 (range 0.81-1.20) and TT-TG distance was 10.1 mm (range 1.8-13.8 mm). The present study demonstrates that beyond replacing arthritic cartilage, trochlear-cutting PFA improves patellofemoral congruence by correcting trochlear dysplasia and standardizing radiological measurements as patellar tilt and TT-TG. The association of lateral patellar facetectomy improves patellar tracking by reducing the patellar tilt. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Results of Infrageniculate Bypasses Using the Profunda Femoris Artery as Inflow Source.

    PubMed

    Illuminati, Giulio; Calio', Francesco G; Pizzardi, Giulia; Pasqua, Rocco; Masci, Federica; Frezzotti, Francesca; Palumbo, Piergaspare; Vietri, Francesco

    2018-02-01

    When the common femoral artery is not accessible for infrainguinal bypass grafting, the profunda femoris artery (PFA) can be a valuable alternative inflow source for distal arterial revascularization. The purpose of this retrospective study was to evaluate the results of infrageniculate bypass grafting via the PFA as inflow source for critical limb ischemia. Between 1994 and 2016, 68 patients, 51 men of a mean age of 74 years, underwent an infrageniculate arterial bypass grafting for critical limb ischemia, using the PFA as inflow site. PFA was exposed at the Scarpa's triangle in 38 patients (56%) and at its medio-crural segment in 30 patients (44%). The distal anastomosis was performed on the infragenicular popliteal artery in 33 patients (48%), the peroneal artery in 14 patients (20%), the tibioperoneal trunk in 8 patients (12%), the posterior tibial artery in 8 patients (12%), and the dorsalis pedis artery in 5 patients (8%). The graft material consisted of a reversed great saphenous vein (GSV) in 62 patients (91%) and a 6-mm polytetrafluoroethylene graft in 6 patients (9%). The median duration of follow-up was 51 months (range, 6-72 months). As main results, postoperative mortality and morbidity, overall late patients' survival, primary grafts' patency, and limb salvage rate were considered. Operative mortality and morbidity were 3% and 4%, respectively. Overall patients' survival, primary patency and limb salvage rate, at 36 and 60 months were, respectively, 62% and 53%, 66% and 59%, and 92% and 77%. The PFA, both exposed at the Scarpa's triangle and at mid-thigh, is an excellent inflow source for infrageniculate revascularizations. It should remain an important part of the technical armamentarium of vascular surgeons, even in the endovascular era. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. A matched-pair comparison of inlay and onlay trochlear designs for patellofemoral arthroplasty: no differences in clinical outcome but less progression of osteoarthritis with inlay designs.

    PubMed

    Feucht, Matthias J; Cotic, Matthias; Beitzel, Knut; Baldini, Julia F; Meidinger, Gebhart; Schöttle, Philip B; Imhoff, Andreas B

    2017-09-01

    To compare clinical and radiographic results after isolated patellofemoral arthroplasty (PFA) using either a second-generation inlay or onlay trochlear design. The hypothesis was that an inlay design will produce better clinical results and less progression of tibiofemoral osteoarthritis (OA) compared to an onlay design. Fifteen consecutive patients undergoing isolated PFA with an onlay design trochlear component (Journey™ PFJ, Smith & Nephew) were matched with 15 patients after isolated PFA with an inlay design trochlear component (HemiCAP ® Wave, Arthrosurface). Matching criteria were age, gender, body mass index, and follow-up period. An independent observer evaluated patients prospectively, whereas data were compared retrospectively. Clinical outcome was assessed using WOMAC, Lysholm score, and pain VAS. Kellgren-Lawrence grading was used to assess progression of tibiofemoral OA. Conversion to total knee arthroplasty was necessary in one patient within each group, leaving 14 patients per group for final evaluation. The mean follow-up was 26 months in the inlay group and 25 months in the onlay group (n.s.). Both groups displayed significant improvements of all clinical scores (p < 0.05). No significant differences were found between the two groups with regard to the clinical outcome and reoperation rate. No significant progression of tibiofemoral OA was observed in the inlay group, whereas 53 % of the onlay group showed progression of medial and/or lateral tibiofemoral OA (p = 0.009). Isolated PFA using either a second-generation inlay or onlay trochlear component significantly improves functional outcome scores and pain. The theoretical advantages of an inlay design did not result in better clinical outcome scores; however, progression of tibiofemoral OA was significantly less common in patients with an inlay trochlear component. This implant design may therefore improve long-term results and survival rates after isolated PFA. III.

  10. Platelet Function Analyzer 100 and Brain Natriuretic Peptide as Biomarkers in Obstructive Hypertrophic Cardiomyopathy.

    PubMed

    Blackshear, Joseph L; Safford, Robert E; Thomas, Colleen S; Bos, J Martijn; Ackerman, Michael J; Geske, Jeffrey B; Ommen, Steve R; Shapiro, Brian P; Johns, Gretchen S

    2018-03-15

    To test dual blood biomarkers compared with electrocardiogram (ECG) for hypertrophic cardiomyopathy (HC) screening, we performed 3 analyses and cut-point assessments. First, we measured platelet function analyzer (PFA)-100 (n = 99) and normalized B-type natriuretic peptide (BNP) or NT-proBNP (BNP/upper limit of normal [ULN], n = 92) in 64 patients with HC and 29 normal controls (NCs). Second, from the regression equation between PFA and gradient (r = 0.77), we derived estimated PFA in a population of 189 patients with functional class I HC in whom measured BNP/ULN and ECG were available, and calculated single and dual biomarker sensitivity and specificity compared with ECG. Finally, we compared BNP/ULN in class I patients based on mutation and familial history status. In 42 patients with obstructive HC versus NCs, there was a slight overlap of PFA and BNP/ULN, but for the product of PFA × BNP/ULN, there was near-complete separation of values. Among patients with class I obstructive HC, estimated PFA × BNP/ULN had a sensitivity of 93% and a specificity of 100%; in latent and nonobstructive HC, sensitivity dropped to 61% and 72%; for ECG in obstructive, latent, and nonobstructive HC, sensitivity was 71%, 34%, and 67%. Functional class I patients with positive (n = 28) and negative (n = 36) sarcomere mutations and a positive (n = 71) or a negative (n = 109) family history had significant elevations of BNP/ULN versus NC, with no between-group differences. In conclusion, PFA and BNP were highly associated with obstructive HC and could potentially be used for screening; BNP was not uniquely elevated in patients with familial versus nonfamilial or mutation-positive versus mutation-negative HC. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Water Quality Research Program: Recent Developments in the Analysis of Metals in Water, Wastewater, and Other Matrices.

    DTIC Science & Technology

    1987-11-01

    for various types of samples and acids. The system features PFA -closed vessels that will tolerate up to 100 psi, a Teflon-lined cavity that reduces...complexes. Selec- tivity is accomplished by masking agents and pH adjustment and sorption on a small XAD-4 resin column. Evaporation of solvent 119...same pH, Cr(VI) is selectively reduced to Cr(III) and accumulated by adsorption at -0.3 V versus SCE (Batley and Matousek 1980). 150. Sorption , ion

  12. A Comparison of Distribution Free and Non-Distribution Free Factor Analysis Methods

    ERIC Educational Resources Information Center

    Ritter, Nicola L.

    2012-01-01

    Many researchers recognize that factor analysis can be conducted on both correlation matrices and variance-covariance matrices. Although most researchers extract factors from non-distribution free or parametric methods, researchers can also extract factors from distribution free or non-parametric methods. The nature of the data dictates the method…

  13. Time Neutron Technique for UXO Discrimination

    DTIC Science & Technology

    2010-12-01

    mixture of TNT and RDX C-4 CFD Composition 4 military plastic explosive Constant Fraction Discriminator Cps CsI counts per second inorganic...Pdfs Probability Density Functions PET Positron Emission Tomography Pfa Probability of False Alarm PFTNA Pulsed Fast/Thermal Neutron Analysis PMTs...the ordnance type (rocket, mortar , projectile, etc.) and what filler material it contains (inert or empty), practice, HE, illumination, chemical (i.e

  14. Factor Analysis of the Modified Sexual Adjustment Questionnaire-Male

    PubMed Central

    Wilmoth, Margaret C.; Hanlon, Alexandra L.; Ng, Lit Soo; Bruner, Debra W.

    2015-01-01

    Background and Purpose The Sexual Adjustment Questionnaire (SAQ) is used in National Cancer Institute–sponsored clinical trials as an outcome measure for sexual functioning. The tool was revised to meet the needs for a clinically useful, theory-based outcome measure for use in both research and clinical settings. This report describes the modifications and validity testing of the modified Sexual Adjustment Questionnaire-Male (mSAQ-Male). Methods This secondary analysis of data from a large Radiation Therapy Oncology Group trial employed principal axis factor analytic techniques in estimating validity of the revised tool. The sample size was 686; most subjects were White, older than the age 60 years, and with a high school education and a Karnofsky performance scale (KPS) score of greater than 90. Results A 16-item, 3-factor solution resulted from the factor analysis. The mSAQ-Male was also found to be sensitive to changes in physical sexual functioning as measured by the KPS. Conclusion The mSAQ-Male is a valid self-report measure of sexuality that can be used clinically to detect changes in male sexual functioning. PMID:25255676

  15. Landslides geotechnical analysis. Qualitative assessment by valuation factors

    NASA Astrophysics Data System (ADS)

    Cuanalo Oscar, Sc D.; Oliva Aldo, Sc D.; Polanco Gabriel, M. E.

    2012-04-01

    In general, a landslide can cause a disaster when it is combined a number of factors such as an extreme event related to a geological phenomenon, vulnerable elements exposed in a specific geographic area, and the probability of loss and damage evaluated in terms of lives and economic assets, in a certain period of time. This paper presents the qualitative evaluation of slope stability through of Valuation Factors, obtained from the characterization of the determinants and triggers factors that influence the instability; for the first the morphology and topography, geology, soil mechanics, hydrogeology and vegetation to the second, the rain, earthquakes, erosion and scour, human activity, and ultimately dependent factors of the stability analysis, and its influence ranges which greatly facilitate the selection of construction processes best suited to improve the behavior of a slope or hillside. The Valuation Factors are a set of parameters for assessing the influence of conditioning and triggering factors that influence the stability of slopes and hillsides. The characteristics of each factor must be properly categorized to involve its effect on behavior; a way to do this is by assigning a weighted value range indicating its effect on the stability of a slope. It is proposed to use Valuation Factors with weighted values between 0 and 1 (arbitrarily selected but common sense and logic), the first corresponds to no or minimal effect on stability (no effect or very little influence) and the second, the greatest impact on it (has a significant influence). The meddle effects are evaluated with intermediate values.

  16. Scale-Free Nonparametric Factor Analysis: A User-Friendly Introduction with Concrete Heuristic Examples.

    ERIC Educational Resources Information Center

    Mittag, Kathleen Cage

    Most researchers using factor analysis extract factors from a matrix of Pearson product-moment correlation coefficients. A method is presented for extracting factors in a non-parametric way, by extracting factors from a matrix of Spearman rho (rank correlation) coefficients. It is possible to factor analyze a matrix of association such that…

  17. Reporting Practices in Confirmatory Factor Analysis: An Overview and Some Recommendations

    ERIC Educational Resources Information Center

    Jackson, Dennis L.; Gillaspy, J. Arthur, Jr.; Purc-Stephenson, Rebecca

    2009-01-01

    Reporting practices in 194 confirmatory factor analysis studies (1,409 factor models) published in American Psychological Association journals from 1998 to 2006 were reviewed and compared with established reporting guidelines. Three research questions were addressed: (a) how do actual reporting practices compare with published guidelines? (b) how…

  18. Factor analysis and Mokken scaling of the Organizational Commitment Questionnaire in nurses.

    PubMed

    Al-Yami, M; Galdas, P; Watson, R

    2018-03-22

    To generate an Arabic version of the Organizational Commitment Questionnaire that would be easily understood by Arabic speakers and would be sensitive to Arabic culture. The nursing workforce in Saudi Arabia is undergoing a process of Saudization but there is a need to understand the factors that will help to retain this workforce. No organizational commitment tools exist in Arabic that are specifically designed for health organizations. An Arabic version of the organizational commitment tool could aid Arabic speaking employers to understand their employees' perceptions of their organizations. Translation and back-translation followed by factor analysis (principal components analysis and confirmatory factor analysis) to test the factorial validity and item response theory (Mokken scaling). A two-factor structure was obtained for the Organizational Commitment Questionnaire comprising Factor 1: Value commitment; and Factor 2: Commitment to stay with acceptable reliability measured by internal consistency. A Mokken scale was obtained including items from both factors showing a hierarchy of items running from commitment to the organization and commitment to self. This study shows that the Arabic version of the OCQ retained the established two-factor structure of the original English-language version. Although the two factors - 'value commitment' and 'commitment to stay' - repudiate the original developers' single factor claim. A useful insight into the structure of the Organizational Commitment Questionnaire has been obtained with the novel addition of a hierarchical scale. The Organizational Commitment Questionnaire is now ready to be used with nurses in the Arab speaking world and could be used a tool to measure the contemporary commitment of nursing employees and in future interventions aimed at increasing commitment and retention of valuable nursing staff. © 2018 International Council of Nurses.

  19. Indonesian railway accidents--utilizing Human Factors Analysis and Classification System in determining potential contributing factors.

    PubMed

    Iridiastadi, Hardianto; Ikatrinasari, Zulfa Fitri

    2012-01-01

    The prevalence of Indonesian railway accidents has not been declining, with hundreds of fatalities reported in the past decade. As an effort to help the National Transportation Safety Committee (NTSC), this study was conducted that aimed at understanding factors that might have contributed to the accidents. Human Factors Analysis and Classification System (HFACS) was utilized for this purpose. A total of nine accident reports (provided by the Indonesian NTSC) involving fatalities were studied using the technique. Results of this study indicated 72 factors that were closely related to the accidents. Of these, roughly 22% were considered as operator acts while about 39% were related to preconditions for operator acts. Supervisory represented 14% of the factors, and the remaining (about 25%) were associated with organizational factors. It was concluded that, while train drivers indeed played an important role in the accidents, interventions solely directed toward train drivers may not be adequate. A more comprehensive approach in minimizing the accidents should be conducted that addresses all the four aspects of HFACS.

  20. Ion mobility based on column leaching of South African gold tailings dam with chemometric evaluation.

    PubMed

    Cukrowska, Ewa M; Govender, Koovila; Viljoen, Morris

    2004-07-01

    New column leaching experiments were designed and used as an alternative rapid screening approach to element mobility assessment. In these experiments, field-moist material was treated with an extracting solution to assess the effects of acidification on element mobility in mine tailings. The main advantage of this version of column leaching experiments with partitioned segments is that they give quick information on current element mobility in conditions closely simulating field conditions to compare with common unrepresentative air-dried, sieved samples used for column leaching experiments. Layers from the tailings dump material were sampled and packed into columns. The design of columns allows extracting leachates from each layer. The extracting solutions used were natural (pH 6.8) and acidified (pH 4.2) rainwater. Metals and anions were determined in the leachates. The concentrations of metals (Ca, Mg, Fe, Mn, Al, Cr, Ni, Co, Zn, and Cu) in sample leachates were determined using ICP OES. The most important anions (NO3-, Cl-, and SO4(2)-) were determined using the closed system izotacophoresis ITP analyser. The chemical analytical data from tailings leaching and physico-chemical data from field measurements (including pH, conductivity, redox potential, temperature) were used for chemometric evaluation of element mobility. Principal factor analysis (PFA) was used to evaluate ions mobility from different layers of tailings dump arising from varied pH and redox conditions. It was found that the results from the partitioned column leaching illustrate much better complex processes of metals mobility from tailings dump than the total column. The chemometric data analysis (PFA) proofed the differences in the various layers leachability that are arising from physico-chemical processes due to chemical composition of tailings dump deposit. Copyright 2004 Elsevier Ltd.

  1. Selective serotonin reuptake inhibitors: measurement of effect on platelet function.

    PubMed

    McCloskey, Donna Jo; Postolache, Teodor T; Vittone, Bernard J; Nghiem, Khanh L; Monsale, Jude L; Wesley, Robert A; Rick, Margaret E

    2008-03-01

    Selective serotonin reuptake inhibitors (SSRIs) reduce platelet serotonin and are associated with increased gastrointestinal bleeding, an effect that is enhanced when taken with NSAIDs or aspirin. The best method to evaluate hemorrhagic events in patients taking SSRIs has not been determined. Platelet aggregation, which is not widely available, shows SSRI inhibition of platelet function; we tested whether a platelet function analyzer could detect SSRI inhibition of platelet function. Two groups of outpatients with mood disorders were recruited; each patient was taking a stable dose of either an SSRI or bupropion for at least 6 weeks. They were tested using the platelet function analyzer-100 (PFA-100; Dade International Inc, Miami, Fla) concomitantly with platelet aggregation. Fifty-eight patients were analyzed. We detected significant differences between the groups using aggregation methods with arachidonic acid (aggregation, P = 0.00001; release, P = 0.009) and collagen (aggregation, P = 0.016; release, P = 0.006). The PFA-100 did not detect differences between the groups or results outside the reference range. The PFA-100 does not detect the inhibitory effects of SSRIs on platelet function, but it can be used to direct evaluation of bleeding in a patient taking an SSRI. Abnormal PFA-100 results suggest additional evaluation for von Willebrand disease, other platelet inhibitory medications, or underlying intrinsic platelet dysfunction.

  2. Replication Analysis in Exploratory Factor Analysis: What It Is and Why It Makes Your Analysis Better

    ERIC Educational Resources Information Center

    Osborne, Jason W.; Fitzpatrick, David C.

    2012-01-01

    Exploratory Factor Analysis (EFA) is a powerful and commonly-used tool for investigating the underlying variable structure of a psychometric instrument. However, there is much controversy in the social sciences with regard to the techniques used in EFA (Ford, MacCallum, & Tait, 1986; Henson & Roberts, 2006) and the reliability of the outcome.…

  3. A factor analysis of the SSQ (Speech, Spatial, and Qualities of Hearing Scale)

    PubMed Central

    2014-01-01

    Objective The speech, spatial, and qualities of hearing questionnaire (SSQ) is a self-report test of auditory disability. The 49 items ask how well a listener would do in many complex listening situations illustrative of real life. The scores on the items are often combined into the three main sections or into 10 pragmatic subscales. We report here a factor analysis of the SSQ that we conducted to further investigate its statistical properties and to determine its structure. Design Statistical factor analysis of questionnaire data, using parallel analysis to determine the number of factors to retain, oblique rotation of factors, and a bootstrap method to estimate the confidence intervals. Study sample 1220 people who have attended MRC IHR over the last decade. Results We found three clear factors, essentially corresponding to the three main sections of the SSQ. They are termed “speech understanding”, “spatial perception”, and “clarity, separation, and identification”. Thirty-five of the SSQ questions were included in the three factors. There was partial evidence for a fourth factor, “effort and concentration”, representing two more questions. Conclusions These results aid in the interpretation and application of the SSQ and indicate potential methods for generating average scores. PMID:24417459

  4. Exploratory factor analysis of the functional movement screen in elite athletes.

    PubMed

    Li, Yongming; Wang, Xiong; Chen, Xiaoping; Dai, Boyi

    2015-01-01

    The functional movement screen is developed to examine individuals' movement patterns through 7 functional tasks. The purpose of this study was to identify the internal consistency and factor structure of the 7 tasks of the functional movement screen in elite athletes; 290 elite athletes from a variety of Chinese national teams were assessed using the functional movement screen. Cronbach's alpha was calculated for the scores of the 7 tasks. Exploratory factor analysis was performed to explore the factor structure of the functional movement screen. The mean and standard deviation of the sum score were 15.2 ± 3.0. A low Cronbach's alpha (0.58) was found for the scores of the 7 tasks. Exploratory factor analysis extracted 2 factors with eigenvalues greater than 1, and these 2 factors explained 47.3% of the total variance. The first factor had a high loading on the rotatory stability (loading = 0.99) and low loadings on the other 6 tasks (loading range: 0.04-0.34). The second factor had high loadings on the deep squat, hurdle step and inline lunge (loading range: 0.46-0.61) and low loadings on the other 3 tasks (loading range: 0.12-0.32). The 7 tasks of the functional movement screen had low internal consistency and were not indicators of a single factor. Evidence for unidimensionality was not found for the functional movement screen in elite athletes. More attention should be paid to the score of each task rather than the sum score when we interpret the functional movement screen scores.

  5. Combined target factor analysis and Bayesian soft-classification of interference-contaminated samples: forensic fire debris analysis.

    PubMed

    Williams, Mary R; Sigman, Michael E; Lewis, Jennifer; Pitan, Kelly McHugh

    2012-10-10

    A bayesian soft classification method combined with target factor analysis (TFA) is described and tested for the analysis of fire debris data. The method relies on analysis of the average mass spectrum across the chromatographic profile (i.e., the total ion spectrum, TIS) from multiple samples taken from a single fire scene. A library of TIS from reference ignitable liquids with assigned ASTM classification is used as the target factors in TFA. The class-conditional distributions of correlations between the target and predicted factors for each ASTM class are represented by kernel functions and analyzed by bayesian decision theory. The soft classification approach assists in assessing the probability that ignitable liquid residue from a specific ASTM E1618 class, is present in a set of samples from a single fire scene, even in the presence of unspecified background contributions from pyrolysis products. The method is demonstrated with sample data sets and then tested on laboratory-scale burn data and large-scale field test burns. The overall performance achieved in laboratory and field test of the method is approximately 80% correct classification of fire debris samples. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  6. Confirmatory factor analysis of the female sexual function index.

    PubMed

    Opperman, Emily A; Benson, Lindsay E; Milhausen, Robin R

    2013-01-01

    The Female Sexual Functioning Index (Rosen et al., 2000 ) was designed to assess the key dimensions of female sexual functioning using six domains: desire, arousal, lubrication, orgasm, satisfaction, and pain. A full-scale score was proposed to represent women's overall sexual function. The fifth revision to the Diagnostic and Statistical Manual (DSM) is currently underway and includes a proposal to combine desire and arousal problems. The objective of this article was to evaluate and compare four models of the Female Sexual Functioning Index: (a) single-factor model, (b) six-factor model, (c) second-order factor model, and (4) five-factor model combining the desire and arousal subscales. Cross-sectional and observational data from 85 women were used to conduct a confirmatory factor analysis on the Female Sexual Functioning Index. Local and global goodness-of-fit measures, the chi-square test of differences, squared multiple correlations, and regression weights were used. The single-factor model fit was not acceptable. The original six-factor model was confirmed, and good model fit was found for the second-order and five-factor models. Delta chi-square tests of differences supported best fit for the six-factor model validating usage of the six domains. However, when revisions are made to the DSM-5, the Female Sexual Functioning Index can adapt to reflect these changes and remain a valid assessment tool for women's sexual functioning, as the five-factor structure was also supported.

  7. Terahertz Technology and Molecular Interactions

    DTIC Science & Technology

    2010-12-16

    numerical identification algorithm, based on a simple threshold model, showed that the probability for false alarm ( PFA ) for the least favorable of...Briefly put, Phase I of MACS was to develop in 18 months a sensor system in a 1 cu ft vol- ume that could correctly identify with a PFA < 10-4 gases in a...observe spectral lines that have fractional ab- sorptions of 10-7 there are six orders of magnitude in sensitivity at stake. If spectral lines have

  8. The School Counseling Program Implementation Survey: Initial Instrument Development and Exploratory Factor Analysis

    ERIC Educational Resources Information Center

    Clemens, Elysia V.; Carey, John C.; Harrington, Karen M.

    2010-01-01

    This article details the initial development of the School Counseling Program Implementation Survey and psychometric results including reliability and factor structure. An exploratory factor analysis revealed a three-factor model that accounted for 54% of the variance of the intercorrelation matrix and a two-factor model that accounted for 47% of…

  9. Exploratory and Confirmatory Factor Analysis of the Career Decision-Making Difficulties Questionnaire

    PubMed Central

    Farrokhi, Farahman; Mahdavi, Ali; Moradi, Samad

    2012-01-01

    Objective The present study aimed at validating the structure of Career Decision-making Difficulties Questionnaire (CDDQ). Methods Five hundred and eleven undergraduate students took part in this research; from these participants, 63 males and 200 females took part in the first study, and 63 males and 185 females completed the survey for the second study. Results The results of exploratory factor analysis (EFA) indicated strong support for the three-factor structure, consisting of lack of information about the self, inconsistent information, lack of information and lack of readiness factors. A confirmatory factor analysis was run with the second sample using structural equation modeling. As expected, the three-factor solution provided a better fit to the data than the alternative models. Conclusion CDDQ was recommended to be used for college students in this study due to the fact that this instrument measures all three aspects of the model. Future research is needed to learn whether this model would fit other different samples. PMID:22952549

  10. Adjusting for multiple prognostic factors in the analysis of randomised trials

    PubMed Central

    2013-01-01

    Background When multiple prognostic factors are adjusted for in the analysis of a randomised trial, it is unclear (1) whether it is necessary to account for each of the strata, formed by all combinations of the prognostic factors (stratified analysis), when randomisation has been balanced within each stratum (stratified randomisation), or whether adjusting for the main effects alone will suffice, and (2) the best method of adjustment in terms of type I error rate and power, irrespective of the randomisation method. Methods We used simulation to (1) determine if a stratified analysis is necessary after stratified randomisation, and (2) to compare different methods of adjustment in terms of power and type I error rate. We considered the following methods of analysis: adjusting for covariates in a regression model, adjusting for each stratum using either fixed or random effects, and Mantel-Haenszel or a stratified Cox model depending on outcome. Results Stratified analysis is required after stratified randomisation to maintain correct type I error rates when (a) there are strong interactions between prognostic factors, and (b) there are approximately equal number of patients in each stratum. However, simulations based on real trial data found that type I error rates were unaffected by the method of analysis (stratified vs unstratified), indicating these conditions were not met in real datasets. Comparison of different analysis methods found that with small sample sizes and a binary or time-to-event outcome, most analysis methods lead to either inflated type I error rates or a reduction in power; the lone exception was a stratified analysis using random effects for strata, which gave nominal type I error rates and adequate power. Conclusions It is unlikely that a stratified analysis is necessary after stratified randomisation except in extreme scenarios. Therefore, the method of analysis (accounting for the strata, or adjusting only for the covariates) will not

  11. Prognostic factors in patients with spinal metastasis: a systematic review and meta-analysis.

    PubMed

    Luksanapruksa, Panya; Buchowski, Jacob M; Hotchkiss, William; Tongsai, Sasima; Wilartratsami, Sirichai; Chotivichit, Areesak

    2017-05-01

    Incidence of symptomatic spinal metastasis has increased owing to improvement in treatment of the disease. One of the key factors that influences decision-making is expected patient survival. To our knowledge, no systematic reviews or meta-analysis have been conducted that review independent prognostic factors in spinal metastases. This study aimed to determine independent prognostic factors that affect outcome in patients with metastatic spine disease. This is a systematic literature review and meta-analysis of publications for prognostic factors in spinal metastatic disease. Pooled patient results from cohort and observational studies. Meta-analysis for poor prognostic factors as determined by hazard ratio (HR) and 95% confidential interval (95% CI). We systematically searched relevant publications in PubMed and Embase. The following search terms were used: ("'spinal metastases'" OR "'vertebral metastases'" OR "spinal metastasis" OR 'vertebral metastases') AND ('"prognostic factors"' OR "'survival'"). Inclusion criteria were prospective and retrospective cohort series that report HR and 95% CI of independent prognostic factors from multivariate analysis. Two reviewers independently assessed all papers. The quality of included papers was assessed by using Newcastle-Ottawa Scale for cohort studies and publication bias was assessed by using funnel plot, Begg test, and Egger test. The prognostic factors that were mentioned in at least three publications were pooled. Meta-analysis was performed using HR and 95% CI as the primary outcomes of interest. Heterogeneity was assessed using the I 2 method. A total of 3,959 abstracts (1,382 from PubMed and 2,577 from Embase) were identified through database search and 40 publications were identified through review of cited publications. The reviewers selected a total of 51 studies for qualitative synthesis and 43 studies for meta-analysis. Seventeen poor prognostic factors were identified. These included presence of a

  12. Confirmatory Factor Analysis of the Elementary School Success Profile for Teachers

    ERIC Educational Resources Information Center

    Webber, Kristina C.; Rizo, Cynthia F.; Bowen, Natasha K.

    2012-01-01

    Objectives: This study examines the factor structure and scale quality of data collected with the online Elementary School Success Profile (ESSP) for Teachers from a sample of teachers of 1,145 third through fifth graders. Methods: Confirmatory factor analysis (CFA) using Mplus and weighted least squares means and variances adjusted (WLSMV)…

  13. The Columbia Impairment Scale: Factor Analysis Using a Community Mental Health Sample

    ERIC Educational Resources Information Center

    Singer, Jonathan B.; Eack, Shaun M.; Greeno, Catherine M.

    2011-01-01

    Objective: The objective of this study was to test the factor structure of the parent version of the Columbia Impairment Scale (CIS) in a sample of mothers who brought their children for community mental health (CMH) services (n = 280). Method: Confirmatory factor analysis (CFA) was used to test the fit of the hypothesized four-factor structure…

  14. Analysis of Performance Factors for Accounting and Finance Related Business Courses in a Distance Education Environment

    ERIC Educational Resources Information Center

    Benligiray, Serdar; Onay, Ahmet

    2017-01-01

    The objective of this study is to explore business courses performance factors with a focus on accounting and finance. Course score interrelations are assumed to represent interpretable constructs of these factors. Factor analysis is proposed to identify the constructs that explain the correlations. Factor analysis results identify three…

  15. Discriminative factor analysis of juvenile delinquency in South Korea.

    PubMed

    Kim, Hyun Sil; Kim, Hun Soo

    2006-12-01

    The present study was intended to compare difference in research variables between delinquent adolescents and student adolescents, and to analyze discriminative factors of delinquent behaviors among Korean adolescents. The research design of this study was a questionnaire survey. Questionnaires were administered to 2,167 adolescents (1,196 students and 971 delinquents), sampled from 8 middle and high school and 6 juvenile corrective institutions, using the proportional stratified random sampling method. Statistical methods employed were Chi-square, t-test, and logistic regression analysis. The discriminative factors of delinquent behaviors were smoking, alcohol use, other drug use, being sexually abused, viewing time of media violence and pornography. Among these discriminative factors, the factor most strongly associated with delinquency was smoking (odds ratio: 32.32). That is, smoking adolescent has a 32-fold higher possibility of becoming a delinquent adolescent than a non-smoking adolescent. Our findings, that smoking was the strongest discriminative factor of delinquent behavior, suggest that educational strategies to prevent adolescent smoking may reduce the rate of juvenile delinquency. Antismoking educational efforts are therefore urgently needed in South Korea.

  16. Evaluating the Mobility of Arsenic in Synthetic Iron-containing Solids Using a Modified Sequential Extraction Method.

    PubMed

    Shan, Jilei; Sáez, A Eduardo; Ela, Wendell P

    2010-02-01

    Many water treatment technologies for arsenic removal that are used today produce arsenic-bearing residuals which are disposed in non-hazardous landfills. Previous works have established that many of these residuals will release arsenic to a much greater extent than predicted by standard regulatory leaching tests (e.g. the toxicity characteristic leaching procedure, TCLP) and, consequently, require stabilization to ensure benign behavior after disposal. In this work, a four-step sequential extraction method was developed in an effort to determine the proportion of arsenic in various phases in untreated as well as stabilized iron-based solid matrices. The solids synthesized using various potential stabilization techniques included: amorphous arsenic-iron sludge (ASL), reduced ASL via reaction with zero valent iron (RASL), amorphous ferrous arsenate (PFA), a mixture of PFA and SL (M1), crystalline ferrous arsenate (HPFA), and a mixture of HPFA and SL (M2). The overall arsenic mobility of the tested samples increased in the following order: ASL > RASL > PFA > M1 > HPFA > M2.

  17. [Comparison between the way of intravenous administration of flagellin from Salmonella typhosa to the margial vein in the ear and into the mesenteric superior vein. Preliminary note].

    PubMed

    Scoglio, M E; Bisignano, G; Fazio, A

    1975-01-01

    Rabbits receiving three injections of PFA intravenously in ear, after that first treatment gave a weak antibody response, after the second one a rapid and copious increase of agglutination titre; the third injection induced a very small increase. In rabbits injected with PFA in superior mesenteric vein the first injection produced a little effect, the second induced a little effect too; the third injection performed in auricular vein, gave a substancial rapid and copious antibody response. This behaviour is similar to that obtained after the second injection in the first set of experiments. The PFA injected two times in mesenteric vein caused certainly a massive phagocytosis of antigen by Kupffer cells. Nevertheless this copious phagocytosis can exercise only an action of "priming", not a response of secondary type. For this purpose it is necessary an injection in the ear vein to provoke a direct intervention of lymphonodal reticular phagocytes. The phenomenon can be related to the proteic nature of the antigen.

  18. A meta-analysis of factors affecting trust in human-robot interaction.

    PubMed

    Hancock, Peter A; Billings, Deborah R; Schaefer, Kristin E; Chen, Jessie Y C; de Visser, Ewart J; Parasuraman, Raja

    2011-10-01

    We evaluate and quantify the effects of human, robot, and environmental factors on perceived trust in human-robot interaction (HRI). To date, reviews of trust in HRI have been qualitative or descriptive. Our quantitative review provides a fundamental empirical foundation to advance both theory and practice. Meta-analytic methods were applied to the available literature on trust and HRI. A total of 29 empirical studies were collected, of which 10 met the selection criteria for correlational analysis and 11 for experimental analysis. These studies provided 69 correlational and 47 experimental effect sizes. The overall correlational effect size for trust was r = +0.26,with an experimental effect size of d = +0.71. The effects of human, robot, and environmental characteristics were examined with an especial evaluation of the robot dimensions of performance and attribute-based factors. The robot performance and attributes were the largest contributors to the development of trust in HRI. Environmental factors played only a moderate role. Factors related to the robot itself, specifically, its performance, had the greatest current association with trust, and environmental factors were moderately associated. There was little evidence for effects of human-related factors. The findings provide quantitative estimates of human, robot, and environmental factors influencing HRI trust. Specifically, the current summary provides effect size estimates that are useful in establishing design and training guidelines with reference to robot-related factors of HRI trust. Furthermore, results indicate that improper trust calibration may be mitigated by the manipulation of robot design. However, many future research needs are identified.

  19. Exploratory factor analysis of self-reported symptoms in a large, population-based military cohort

    PubMed Central

    2010-01-01

    Background US military engagements have consistently raised concern over the array of health outcomes experienced by service members postdeployment. Exploratory factor analysis has been used in studies of 1991 Gulf War-related illnesses, and may increase understanding of symptoms and health outcomes associated with current military conflicts in Iraq and Afghanistan. The objective of this study was to use exploratory factor analysis to describe the correlations among numerous physical and psychological symptoms in terms of a smaller number of unobserved variables or factors. Methods The Millennium Cohort Study collects extensive self-reported health data from a large, population-based military cohort, providing a unique opportunity to investigate the interrelationships of numerous physical and psychological symptoms among US military personnel. This study used data from the Millennium Cohort Study, a large, population-based military cohort. Exploratory factor analysis was used to examine the covariance structure of symptoms reported by approximately 50,000 cohort members during 2004-2006. Analyses incorporated 89 symptoms, including responses to several validated instruments embedded in the questionnaire. Techniques accommodated the categorical and sometimes incomplete nature of the survey data. Results A 14-factor model accounted for 60 percent of the total variance in symptoms data and included factors related to several physical, psychological, and behavioral constructs. A notable finding was that many factors appeared to load in accordance with symptom co-location within the survey instrument, highlighting the difficulty in disassociating the effects of question content, location, and response format on factor structure. Conclusions This study demonstrates the potential strengths and weaknesses of exploratory factor analysis to heighten understanding of the complex associations among symptoms. Further research is needed to investigate the relationship between

  20. Human Factors Analysis of Pipeline Monitoring and Control Operations: Final Technical Report

    DOT National Transportation Integrated Search

    2008-11-26

    The purpose of the Human Factors Analysis of Pipeline Monitoring and Control Operations project was to develop procedures that could be used by liquid pipeline operators to assess and manage the human factors risks in their control rooms that may adv...

  1. Risk factors for chronic and recurrent otitis media-a meta-analysis.

    PubMed

    Zhang, Yan; Xu, Min; Zhang, Jin; Zeng, Lingxia; Wang, Yanfei; Zheng, Qing Yin

    2014-01-01

    Risk factors associated with chronic otitis media (COM) and recurrent otitis media (ROM) have been investigated in previous studies. The objective of this study was to integrate the findings and determine the possible risk factors for COM/ROM based on our meta-analysis. A comprehensive search of electronic bibliographic databases (PubMed, Embase, CNKI and Wanfang database) from 1964 to Dec 2012, as well as a manual search of references of articles, was performed. A total of 2971 articles were searched, and 198 full-text articles were assessed for eligibility; 24 studies were eligible for this meta-analysis. Regarding risk factors for COM/ROM, there were two to nine different studies from which the odds ratios (ORs) could be pooled. The presence of allergy or atopy increased the risk of COM/ROM (OR, 1.36; 95% CI, 1.13-1.64; P = 0.001). An upper respiratory tract infection (URTI) significantly increased the risk of COM/ROM (OR, 6.59; 95% CI, 3.13-13.89; P<0.00001). Snoring appeared to be a significant risk factor for COM/ROM (OR, 1.96; 95% CI, 1.78-2.16; P<0.00001). A patient history of acute otitis media (AOM)/ROM increased the risk of COM/ROM (OR, 11.13; 95% CI, 1.06-116.44; P = 0.04). Passive smoke significantly increased the risk of COM/ROM (OR, 1.39; 95% CI, 1.02-1.89 P = 0.04). Low social status appeared to be a risk factor for COM/ROM (OR, 3.82; 95% CI, 1.11-13.15; P = 0.03). Our meta-analysis identified reliable conclusions that allergy/atopy, URTI, snoring, previous history of AOM/ROM, Second-hand smoke and low social status are important risk factors for COM/ROM. Other unidentified risk factors need to be identified in further studies with critical criteria.

  2. Risk Factors for Chronic and Recurrent Otitis Media–A Meta-Analysis

    PubMed Central

    Zhang, Yan; Xu, Min; Zhang, Jin; Zeng, Lingxia; Wang, Yanfei; Zheng, Qing Yin

    2014-01-01

    Risk factors associated with chronic otitis media (COM) and recurrent otitis media (ROM) have been investigated in previous studies. The objective of this study was to integrate the findings and determine the possible risk factors for COM/ROM based on our meta-analysis. A comprehensive search of electronic bibliographic databases (PubMed, Embase, CNKI and Wanfang database) from 1964 to Dec 2012, as well as a manual search of references of articles, was performed. A total of 2971 articles were searched, and 198 full-text articles were assessed for eligibility; 24 studies were eligible for this meta-analysis. Regarding risk factors for COM/ROM, there were two to nine different studies from which the odds ratios (ORs) could be pooled. The presence of allergy or atopy increased the risk of COM/ROM (OR, 1.36; 95% CI, 1.13–1.64; P = 0.001). An upper respiratory tract infection (URTI) significantly increased the risk of COM/ROM (OR, 6.59; 95% CI, 3.13–13.89; P<0.00001). Snoring appeared to be a significant risk factor for COM/ROM (OR, 1.96; 95% CI, 1.78–2.16; P<0.00001). A patient history of acute otitis media (AOM)/ROM increased the risk of COM/ROM (OR, 11.13; 95% CI, 1.06–116.44; P = 0.04). Passive smoke significantly increased the risk of COM/ROM (OR, 1.39; 95% CI, 1.02–1.89 P = 0.04). Low social status appeared to be a risk factor for COM/ROM (OR, 3.82; 95% CI, 1.11–13.15; P = 0.03). Our meta-analysis identified reliable conclusions that allergy/atopy, URTI, snoring, previous history of AOM/ROM, Second-hand smoke and low social status are important risk factors for COM/ROM. Other unidentified risk factors need to be identified in further studies with critical criteria. PMID:24466073

  3. Exploratory factor analysis of the Research and Development Culture Index among qualified nurses.

    PubMed

    Watson, Bill; Clarke, Charlotte; Swallow, Vera; Forster, Stewart

    2005-10-01

    This paper presents the exploratory factor analysis of a rating instrument for assessing the strength of organizational Research and Development (R&D) culture. Despite nursing's limited research capacity, the discipline is capitalizing upon opportunities to become involved in research and is making strong progress. Within the context of the debate on nursing research capacity, the R&D Culture Index was developed as a means of appraising R&D culture within health care organizations. Factor analysis was carried out on data collected from 485 nursing staff. The method of extraction was Principal Components Analysis with oblique rotation. The Index was developed from the findings of qualitative research conducted with NHS staff. Eighteen items, encompassing the main themes from the data, were initially included in the Index. This pilot instrument was distributed to nursing staff within three different types of NHS Trust. Factor analysis resulted in rejection of two items and the analysis was repeated using the remaining 16 items. Three latent factors were extracted accounting for 58.0% of the variance in the data. The factors were: R&D Support, describing the perceived support within the working environment for R&D activity; Personal R&D Skills and Aptitude, describing an individual's perception of their ability towards R&D activity; and Personal R&D Intention, describing an individual's willingness to engage in R&D activity. Each factor had good internal reliability, as did the overall index. The R&D Culture Index provides an efficient means of assessing the strength of an organization's R&D culture in a way that captures the role of the individual practitioner and the organizational environment. These findings suggest that the continuing promotion of R&D within health care organizations is dependent upon a multi-faceted approach that addresses the learning needs of the organization as well as those of the individual practitioners.

  4. Arabidopsis transcription factors: genome-wide comparative analysis among eukaryotes.

    PubMed

    Riechmann, J L; Heard, J; Martin, G; Reuber, L; Jiang, C; Keddie, J; Adam, L; Pineda, O; Ratcliffe, O J; Samaha, R R; Creelman, R; Pilgrim, M; Broun, P; Zhang, J Z; Ghandehari, D; Sherman, B K; Yu, G

    2000-12-15

    The completion of the Arabidopsis thaliana genome sequence allows a comparative analysis of transcriptional regulators across the three eukaryotic kingdoms. Arabidopsis dedicates over 5% of its genome to code for more than 1500 transcription factors, about 45% of which are from families specific to plants. Arabidopsis transcription factors that belong to families common to all eukaryotes do not share significant similarity with those of the other kingdoms beyond the conserved DNA binding domains, many of which have been arranged in combinations specific to each lineage. The genome-wide comparison reveals the evolutionary generation of diversity in the regulation of transcription.

  5. Confirmatory factor analysis of posttraumatic stress symptoms in sexually harassed women.

    PubMed

    Palmieri, Patrick A; Fitzgerald, Louise F

    2005-12-01

    Posttraumatic stress disorder (PTSD) factor analytic research to date has not provided a clear consensus on the structure of posttraumatic stress symptoms. Seven hypothesized factor structures were evaluated using confirmatory factor analysis of the Posttraumatic Stress Disorder Checklist, a paper-and-pencil measure of posttraumatic stress symptom severity, in a sample of 1,218 women who experienced a broad range of workplace sexual harassment. The model specifying correlated re-experiencing, effortful avoidance, emotional numbing, and hyperarousal factors provided the best fit to the data. Virtually no support was obtained for the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV; American Psychiatric Association, 1994) three-factor model of re-experiencing, avoidance, and hyperarousal factors. Different patterns of correlations with external variables were found for the avoidance and emotional numbing factors, providing further validation of the supported model.

  6. Developing Multidimensional Likert Scales Using Item Factor Analysis: The Case of Four-Point Items

    ERIC Educational Resources Information Center

    Asún, Rodrigo A.; Rdz-Navarro, Karina; Alvarado, Jesús M.

    2016-01-01

    This study compares the performance of two approaches in analysing four-point Likert rating scales with a factorial model: the classical factor analysis (FA) and the item factor analysis (IFA). For FA, maximum likelihood and weighted least squares estimations using Pearson correlation matrices among items are compared. For IFA, diagonally weighted…

  7. Sampling factors influencing accuracy of sperm kinematic analysis.

    PubMed

    Owen, D H; Katz, D F

    1993-01-01

    Sampling conditions that influence the accuracy of experimental measurement of sperm head kinematics were studied by computer simulation methods. Several archetypal sperm trajectories were studied. First, mathematical models of typical flagellar beats were input to hydrodynamic equations of sperm motion. The instantaneous swimming velocities of such sperm were computed over sequences of flagellar beat cycles, from which the resulting trajectories were determined. In a second, idealized approach, direct mathematical models of trajectories were utilized, based upon similarities to the previous hydrodynamic constructs. In general, it was found that analyses of sampling factors produced similar results for the hydrodynamic and idealized trajectories. A number of experimental sampling factors were studied, including the number of sperm head positions measured per flagellar beat, and the time interval over which these measurements are taken. It was found that when one flagellar beat is sampled, values of amplitude of lateral head displacement (ALH) and linearity (LIN) approached their actual values when five or more sample points per beat were taken. Mean angular displacement (MAD) values, however, remained sensitive to sampling rate even when large sampling rates were used. Values of MAD were also much more sensitive to the initial starting point of the sampling procedure than were ALH or LIN. On the basis of these analyses of measurement accuracy for individual sperm, simulations were then performed of cumulative effects when studying entire populations of motile cells. It was found that substantial (double digit) errors occurred in the mean values of curvilinear velocity (VCL), LIN, and MAD under the conditions of 30 video frames per second and 0.5 seconds of analysis time. Increasing the analysis interval to 1 second did not appreciably improve the results. However, increasing the analysis rate to 60 frames per second significantly reduced the errors. These findings

  8. A Confirmatory Factor Analysis of the Professional Opinion Scale

    ERIC Educational Resources Information Center

    Greeno, Elizabeth J.; Hughes, Anne K.; Hayward, R. Anna; Parker, Karen L.

    2007-01-01

    The Professional Opinion Scale (POS) was developed to measure social work values orientation. Objective: A confirmatory factor analysis was performed on the POS. Method: This cross-sectional study used a mailed survey design with a national random (simple) sample of members of the National Association of Social Workers. Results: The study…

  9. Final Technical Report: Advanced Measurement and Analysis of PV Derate Factors.

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

    King, Bruce Hardison; Burton, Patrick D.; Hansen, Clifford

    2015-12-01

    The Advanced Measurement and Analysis of PV Derate Factors project focuses on improving the accuracy and reducing the uncertainty of PV performance model predictions by addressing a common element of all PV performance models referred to as “derates”. Widespread use of “rules of thumb”, combined with significant uncertainty regarding appropriate values for these factors contribute to uncertainty in projected energy production.

  10. Method for factor analysis of GC/MS data

    DOEpatents

    Van Benthem, Mark H; Kotula, Paul G; Keenan, Michael R

    2012-09-11

    The method of the present invention provides a fast, robust, and automated multivariate statistical analysis of gas chromatography/mass spectroscopy (GC/MS) data sets. The method can involve systematic elimination of undesired, saturated peak masses to yield data that follow a linear, additive model. The cleaned data can then be subjected to a combination of PCA and orthogonal factor rotation followed by refinement with MCR-ALS to yield highly interpretable results.

  11. Diagnosis of Swallowing Disorders: How We Interpret Pharyngeal Manometry.

    PubMed

    Cock, Charles; Omari, Taher

    2017-03-01

    We provide an overview of the clinical application of novel pharyngeal high-resolution impedance manometry (HRIM) with pressure flow analysis (PFA) in our hands with example cases. In our Centre, we base our interpretation of HRIM recordings upon a qualitative assessment of pressure-impedance waveforms during individual swallows, as well as a quantitative assessment of averaged PFA swallow function variables. We provide a description of two global swallowing efficacy measures, the swallow risk index (SRI), reflecting global swallowing dysfunction (higher SRI = greater aspiration risk) and the post-swallow impedance ratio (PSIR) detecting significant post-swallow bolus residue. We describe a further eight swallow function variables specific to the hypopharynx and upper esophageal sphincter (UES), assessing hypo-pharyngeal distension pressure, contractility, bolus presence and flow timing, and UES basal tone, relaxation, opening and contractility. Pharyngeal HRIM has now come of age, being applicable for routine clinical practice to assess the biomechanics of oropharyngeal swallowing dysfunction. In the future, it may guide treatment strategies and allow more objective longitudinal follow-up on clinical outcomes.

  12. Caution on the storage of waters and aqueous solutions in plastic containers for hydrogen and oxygen stable isotope analysis.

    PubMed

    Spangenberg, Jorge E

    2012-11-30

    The choice of containers for storage of aqueous samples between their collection, transport and water hydrogen ((2)H) and oxygen ((18)O) stable isotope analysis is a topic of concern for a wide range of fields in environmental, geological, biomedical, food, and forensic sciences. The transport and separation of water molecules during water vapor or liquid uptake by sorption or solution and the diffusive transport of water molecules through organic polymer material by permeation or pervaporation may entail an isotopic fractionation. An experiment was conducted to evaluate the extent of such fractionation. Sixteen bottle-like containers of eleven different organic polymers, including low and high density polyethylene (LDPE and HDPE), polypropylene (PP), polycarbonate (PC), polyethylene terephthalate (PET), and perfluoroalkoxy-Teflon (PFA), of different wall thickness and size were completely filled with the same mineral water and stored for 659 days under the same conditions of temperature and humidity. Particular care was exercised to keep the bottles tightly closed and prevent loss of water vapor through the seals. Changes of up to +5‰ for δ(2)H values and +2.0‰ for δ(18)O values were measured for water after more than 1 year of storage within a plastic container, with the magnitude of change depending mainly on the type of organic polymer, wall thickness, and container size. The most important variations were measured for the PET and PC bottles. Waters stored in glass bottles with Polyseal™ cone-lined PP screw caps and thick-walled HDPE or PFA containers with linerless screw caps having an integrally molded inner sealing ring preserved their original δ(2)H and δ(18)O values. The carbon, hydrogen, and oxygen stable isotope compositions of the organic polymeric materials were also determined. The results of this study clearly show that for precise and accurate measurements of the water stable isotope composition in aqueous solutions, rigorous sampling and

  13. A Confirmatory Factor Analysis of the Academic Motivation Scale with Black College Students

    ERIC Educational Resources Information Center

    Cokley, Kevin

    2015-01-01

    The factor structure of the Academic Motivation Scale (AMS) was examined with a sample of 578 Black college students. A confirmatory factor analysis of the AMS was conducted. Results indicated that the hypothesized seven-factor model did not fit the data. Implications for future research with the AMS are discussed.

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

    DOREN,NEALL E.

    Wavefront curvature defocus effects occur in spotlight-mode SAR imagery when reconstructed via the well-known polar-formatting algorithm (PFA) under certain imaging scenarios. These include imaging at close range, using a very low radar center frequency, utilizing high resolution, and/or imaging very large scenes. Wavefront curvature effects arise from the unrealistic assumption of strictly planar wavefronts illuminating the imaged scene. This dissertation presents a method for the correction of wavefront curvature defocus effects under these scenarios, concentrating on the generalized: squint-mode imaging scenario and its computational aspects. This correction is accomplished through an efficient one-dimensional, image domain filter applied as a post-processingmore » step to PF.4. This post-filter, referred to as SVPF, is precalculated from a theoretical derivation of the wavefront curvature effect and varies as a function of scene location. Prior to SVPF, severe restrictions were placed on the imaged scene size in order to avoid defocus effects under these scenarios when using PFA. The SVPF algorithm eliminates the need for scene size restrictions when wavefront curvature effects are present, correcting for wavefront curvature in broadside as well as squinted collection modes while imposing little additional computational penalty for squinted images. This dissertation covers the theoretical development, implementation and analysis of the generalized, squint-mode SVPF algorithm (of which broadside-mode is a special case) and provides examples of its capabilities and limitations as well as offering guidelines for maximizing its computational efficiency. Tradeoffs between the PFA/SVPF combination and other spotlight-mode SAR image formation techniques are discussed with regard to computational burden, image quality, and imaging geometry constraints. It is demonstrated that other methods fail to exhibit a clear computational advantage over polar-formatting in

  15. Analysis of the financial factors governing the profitability of lunar helium-3

    NASA Technical Reports Server (NTRS)

    Kulcinski, G. L.; Thompson, H.; Ott, S.

    1989-01-01

    Financial factors influencing the profitability of the mining and utilization of lunar helium-3 are examined. The analysis addressed the following questions: (1) which financial factors have the greatest leverage on the profitability of He-3; (2) over what range can these factors be varied to keep the He-3 option profitable; and (3) what ultimate effect could this energy source have on the price of electricity for U.S. consumers. Two complementary methods of analysis were used in the assessment: rate of return on incremental investment required and reduction revenue requirements (total cost to customers) achieved. Some of the factors addressed include energy demand, power generation costs with and without fusion, profitability for D-He(3) fusion, annual capital and operating costs, launch mass and costs, He-3 price, and government funding. Specific conclusions are made with respect to each of the companies considered: utilities, lunar mining company, and integrated energy company.

  16. Entrance and exit region friction factor models for annular seal analysis. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Elrod, David Alan

    1988-01-01

    The Mach number definition and boundary conditions in Nelson's nominally-centered, annular gas seal analysis are revised. A method is described for determining the wall shear stress characteristics of an annular gas seal experimentally. Two friction factor models are developed for annular seal analysis; one model is based on flat-plate flow theory; the other uses empirical entrance and exit region friction factors. The friction factor predictions of the models are compared to experimental results. Each friction model is used in an annular gas seal analysis. The seal characteristics predicted by the two seal analyses are compared to experimental results and to the predictions of Nelson's analysis. The comparisons are for smooth-rotor seals with smooth and honeycomb stators. The comparisons show that the analysis which uses empirical entrance and exit region shear stress models predicts the static and stability characteristics of annular gas seals better than the other analyses. The analyses predict direct stiffness poorly.

  17. Analysis on factors affecting consumers decision on purchasing simple-type houses

    NASA Astrophysics Data System (ADS)

    Rumintang, A.; Sholichin, I.

    2018-01-01

    In line with the increase of the population and the need of comfortable houses, as affected by modernization era, the house demand is getting higher. Hence, conducting a research on consumers need and want in buying a house should be seriously attempted to succeed marketing activity. Using an analysis consumers’ behavior, the researcher will know few affecting factors related to consumers’ satisfaction in buying a house. Among other, the factors in question include: house price, house condition, facilities, location and accessability. The sample of this research was drawn from the residents of Graha Asri Housing, Taman Bulang Permai, and Sukodono Permai. Based on the analysis and discussion, some conclusions are made as follow: the factors and variables affecting the consumers’ decision on each choice of house is different and also the same variables on three sources of data include housing atmosphere, cleaning service, ease of access to shopping center, health clinics or hospitals, tourism spot, schools, and the bus station.

  18. In vitro analysis of platelet function in acute aneurysmal subarachnoid haemorrhage.

    PubMed

    von der Brelie, Christian; Subai, Alexander; Limperger, Verena; Rohde, Veit; Dempfle, Astrid; Boström, Azize

    2018-04-01

    Platelet function might play an essential role in the pathogenesis of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid haemorrhage (SAH). Thus, impaired platelet function and disturbed primary haemostasis induced by intake of acetylsalicylic acid (ASA) might influence the rate of DCI. Primary haemostasis and platelet function can be measured with in vitro diagnosis (platelet function analyser test, PFA 100). The aim of this study is to evaluate the rate of DCI, haemorrhagic complications and the neurological outcome. Two groups were compared (patients with regular platelet function versus patients with impaired platelet function). This is a retrospective observational study. An initial cohort of 787 patients with SAH has been treated from January 2005 to September 2012. Seventy-nine patients (10%) with aneurysmal SAH, a history of ASA medication and PFA testing within the first 24 h after aneurysm rupture have been included. The overall rate of DCI in the present study was 43%. In vitro platelet function testing showed pathological primary haemostasis in 69.6%. The DCI rate was higher in patients with regular tested primary haemostasis (p = 0.02, OR = 3.16, 95%CI = [1.19; 8.83]). However, outcome assessment by mGOS did not show a significant difference between the groups. Patients with impaired primary haemostasis did not display a higher rate of haemorrhagic complications. Impairment of primary haemostasis resulting from an impairment of platelet function at an early stage after SAH might lead to a lower rate of DCI. In vitro testing of platelet function might be useful to predict the occurrence of DCI in the course.

  19. An Analysis of Factors That Affect the Educational Performance of Agricultural Students

    ERIC Educational Resources Information Center

    Greenway, Gina

    2012-01-01

    Many factors contribute to student achievement. This study focuses on three areas: how students learn, how student personality type affects performance, and how course format affects performance outcomes. The analysis sought to improve understanding of the direction and magnitude with which each of these factors impacts student success. Improved…

  20. Schizophrenia with prominent catatonic features ('catatonic schizophrenia'). II. Factor analysis of the catatonic syndrome.

    PubMed

    Ungvari, Gabor S; Goggins, William; Leung, Siu-Kau; Gerevich, Jozsef

    2007-03-30

    Previous factor analyses of catatonia have yielded conflicting results for several reasons including small and/or diagnostically heterogeneous samples and incomparability or lack of standardized assessment. This study examined the factor structure of catatonia in a large, diagnostically homogenous sample of patients with chronic schizophrenia using standardized rating instruments. A random sample of 225 Chinese inpatients diagnosed with schizophrenia according to DSM-IV criteria were selected from the long-stay wards of a psychiatric hospital. They were assessed with a battery of rating scales measuring psychopathology, extrapyramidal motor status, and level of functioning. Catatonia was rated using the Bush-Francis Catatonia Rating Scale. Factor analysis using principal component analysis and Varimax rotation with Kaiser normalization was performed. Four factors were identified with Eigenvalues of 3.27, 2.58, 2.28 and 1.88. The percentage of variance explained by each of the four factors was 15.9%, 12.0%, 11.8% and 10.2% respectively, and together they explained 49.9% of the total variance. Factor 1 loaded on "negative/withdrawn" phenomena, Factor 2 on "automatic" phenomena, Factor 3 on "repetitive/echo" phenomena and Factor 4 on "agitated/resistive" phenomena. In multivariate linear regression analysis negative symptoms and akinesia were associated with 'negative' catatonic symptoms, antipsychotic doses and atypical antipsychotics with 'automatic' symptoms, length of current admission, severity of psychopathology and younger age at onset with 'repetitive' symptoms and age, poor functioning and severity of psychopathology with 'agitated' catatonic symptom scores. The results support recent findings that four main factors underlie catatonic signs/symptoms in chronic schizophrenia.

  1. Effects of carprofen, meloxicam and deracoxib on platelet function in dogs.

    PubMed

    Mullins, Kathleen B; Thomason, John M; Lunsford, Kari V; Pinchuk, Lesya M; Langston, Vernon C; Wills, Robert W; McLaughlin, Ronald M; Mackin, Andrew J

    2012-03-01

    To determine effects of anti-inflammatory doses of COX-2 selective NSAIDs carprofen, meloxicam, and deracoxib on platelet function in dogs and urine 11-dehydro-thromboxane B2. Randomized, blocked, crossover design with a 14-day washout period. Healthy intact female Walker Hounds aged 1-6 years and weighing 20.5-24.2 kg. Dogs were given NSAIDs for 7 days at recommended doses: carprofen (2.2 mg kg(-1), PO, every 12 hours), carprofen (4.4 mg kg(-1), PO, every 24 hours), meloxicam (0.2 mg kg(-1), PO, on the 1st day then 0.1 mg kg(-1), PO, every 24 hours), and deracoxib (2 mg kg(-1), PO, every 24 hours). Collagen/epinephrine and collagen/ADP PFA-100 cartridges were used to evaluate platelet function before and during and every other day after administration of each drug. Urine 11-dehydro-thromboxane B(2) was also measured before and during administration of each drug. All NSAIDs significantly prolonged PFA-100 closure times when measured with collagen/epinephrine cartridges, but not with collagen/ADP cartridges. The average duration from drug cessation until return of closure times (collagen/epinephrine cartridges) to baseline values was 11.6, 10.6, 11 and 10.6 days for carprofen (2.2 mg kg(-1) every 12 hours), carprofen (4.4 mg kg(-1) every 24 hours), meloxicam and deracoxib, respectively. Oral administration of some COX-2 selective NSAIDs causes detectable alterations in platelet function in dogs. As in humans, PFA-100 collagen/ADP cartridges do not reliably detect COX-mediated platelet dysfunction in dogs. Individual assessment of platelet function is advised when administering these drugs prior to surgery, particularly in the presence of other risk factors for bleeding. © 2011 The Authors. Veterinary Anaesthesia and Analgesia. © 2011 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesiologists.

  2. Confirmatory Factor Analysis of the WISC-IV in a Hospital Referral Sample

    ERIC Educational Resources Information Center

    Devena, Sarah E.; Gay, Catherine E.; Watkins, Marley W.

    2013-01-01

    Confirmatory factor analysis was used to determine the factor structure of the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) scores of 297 children referred to a children's hospital in the Southwestern United States. Results support previous findings that indicate the WISC-IV is best represented by a direct hierarchical…

  3. A Confirmatory Factor Analysis of Reilly's Role Overload Scale

    ERIC Educational Resources Information Center

    Thiagarajan, Palaniappan; Chakrabarty, Subhra; Taylor, Ronald D.

    2006-01-01

    In 1982, Reilly developed a 13-item scale to measure role overload. This scale has been widely used, but most studies did not assess the unidimensionality of the scale. Given the significance of unidimensionality in scale development, the current study reports a confirmatory factor analysis of the 13-item scale in two samples. Based on the…

  4. Beyond factor analysis: Multidimensionality and the Parkinson's Disease Sleep Scale-Revised.

    PubMed

    Pushpanathan, Maria E; Loftus, Andrea M; Gasson, Natalie; Thomas, Meghan G; Timms, Caitlin F; Olaithe, Michelle; Bucks, Romola S

    2018-01-01

    Many studies have sought to describe the relationship between sleep disturbance and cognition in Parkinson's disease (PD). The Parkinson's Disease Sleep Scale (PDSS) and its variants (the Parkinson's disease Sleep Scale-Revised; PDSS-R, and the Parkinson's Disease Sleep Scale-2; PDSS-2) quantify a range of symptoms impacting sleep in only 15 items. However, data from these scales may be problematic as included items have considerable conceptual breadth, and there may be overlap in the constructs assessed. Multidimensional measurement models, accounting for the tendency for items to measure multiple constructs, may be useful more accurately to model variance than traditional confirmatory factor analysis. In the present study, we tested the hypothesis that a multidimensional model (a bifactor model) is more appropriate than traditional factor analysis for data generated by these types of scales, using data collected using the PDSS-R as an exemplar. 166 participants diagnosed with idiopathic PD participated in this study. Using PDSS-R data, we compared three models: a unidimensional model; a 3-factor model consisting of sub-factors measuring insomnia, motor symptoms and obstructive sleep apnoea (OSA) and REM sleep behaviour disorder (RBD) symptoms; and, a confirmatory bifactor model with both a general factor and the same three sub-factors. Only the confirmatory bifactor model achieved satisfactory model fit, suggesting that PDSS-R data are multidimensional. There were differential associations between factor scores and patient characteristics, suggesting that some PDSS-R items, but not others, are influenced by mood and personality in addition to sleep symptoms. Multidimensional measurement models may also be a helpful tool in the PDSS and the PDSS-2 scales and may improve the sensitivity of these instruments.

  5. Metropolis-Hastings Robbins-Monro Algorithm for Confirmatory Item Factor Analysis

    ERIC Educational Resources Information Center

    Cai, Li

    2010-01-01

    Item factor analysis (IFA), already well established in educational measurement, is increasingly applied to psychological measurement in research settings. However, high-dimensional confirmatory IFA remains a numerical challenge. The current research extends the Metropolis-Hastings Robbins-Monro (MH-RM) algorithm, initially proposed for…

  6. Incidence and risk factors of bleeding-related adverse events in patients with chronic lymphocytic leukemia treated with ibrutinib.

    PubMed

    Lipsky, Andrew H; Farooqui, Mohammed Z H; Tian, Xin; Martyr, Sabrina; Cullinane, Ann M; Nghiem, Khanh; Sun, Clare; Valdez, Janet; Niemann, Carsten U; Herman, Sarah E M; Saba, Nakhle; Soto, Susan; Marti, Gerald; Uzel, Gulbu; Holland, Steve M; Lozier, Jay N; Wiestner, Adrian

    2015-12-01

    Ibrutinib is associated with bleeding-related adverse events of grade ≤ 2 in severity, and infrequently with grade ≥ 3 events. To investigate the mechanisms of bleeding and identify patients at risk, we prospectively assessed platelet function and coagulation factors in our investigator-initiated trial of single-agent ibrutinib for chronic lymphocytic leukemia. At a median follow-up of 24 months we recorded grade ≤ 2 bleeding-related adverse events in 55% of 85 patients. No grade ≥ 3 events occurred. Median time to event was 49 days. The cumulative incidence of an event plateaued by 6 months, suggesting that the risk of bleeding decreases with continued therapy. At baseline, von Willebrand factor and factor VIII levels were often high and normalized on treatment. Platelet function measured via the platelet function analyzer (PFA-100™) was impaired in 22 patients at baseline and in an additional 19 patients on ibrutinib (often transiently). Collagen and adenosine diphosphate induced platelet aggregation was tested using whole blood aggregometry. Compared to normal controls, response to both agonists was decreased in all patients with chronic lymphocytic leukemia, whether on ibrutinib or not. Compared to untreated chronic lymphocytic leukemia patients, response to collagen showed a mild further decrement on ibrutinib, while response to adenosine diphosphate improved. All parameters associated with a significantly increased risk of bleeding-related events were present at baseline, including prolonged epinephrine closure time (HR 2.74, P=0.012), lower levels of von Willebrand factor activity (HR 2.73, P=0.009) and factor VIII (HR 3.73, P=0.0004). In conclusion, both disease and treatment-related factors influence the risk of bleeding. Patients at greater risk for bleeding of grade ≤ 2 can be identified by clinical laboratory tests and counseled to avoid aspirin, non-steroidal anti-inflammatory drugs and fish oils. ClinicalTrials.gov identifier NCT01500733

  7. Mechanisms of Cellular Membrane Effects of TCDD (2,3,7,8-Tetrachlorodibenzo-p-Dioxin) Selected Perfluorinated Acids and Polyhalogenated Aromatic Hydrocarbons.

    DTIC Science & Technology

    1986-10-15

    tetrachloro dibenzo-p-dioxin (TCDD); dioxin; perfluoro -n-decanoic acid ( PFDA ); perfluoro -n-octanoic acid ( PFOA ); 3,31,4,41,5,51 hexachlorobiphenyl (345PCB) and...analysis of livers from rats treated with perfluoro -n-decanoic acid ( PFDA ) showed a decrease in stearic acid and an increase in 18 carbon unsaturates...effects of TCDD, PHAH and perfluorinated acids ( PFA ) on mammalian cell membrane function by examing the phenomenon of metabolic cooperation. Metabolic

  8. The effects of common risk factors on stock returns: A detrended cross-correlation analysis

    NASA Astrophysics Data System (ADS)

    Ruan, Qingsong; Yang, Bingchan

    2017-10-01

    In this paper, we investigate the cross-correlations between Fama and French three factors and the return of American industries on the basis of cross-correlation statistic test and multifractal detrended cross-correlation analysis (MF-DCCA). Qualitatively, we find that the return series of Fama and French three factors and American industries were overall significantly cross-correlated based on the analysis of a statistic. Quantitatively, we find that the cross-correlations between three factors and the return of American industries were strongly multifractal, and applying MF-DCCA we also investigate the cross-correlation of industry returns and residuals. We find that there exists multifractality of industry returns and residuals. The result of correlation coefficients we can verify that there exist other factors which influence the industry returns except Fama three factors.

  9. Spatial Dependence and Heterogeneity in Bayesian Factor Analysis: A Cross-National Investigation of Schwartz Values

    ERIC Educational Resources Information Center

    Stakhovych, Stanislav; Bijmolt, Tammo H. A.; Wedel, Michel

    2012-01-01

    In this article, we present a Bayesian spatial factor analysis model. We extend previous work on confirmatory factor analysis by including geographically distributed latent variables and accounting for heterogeneity and spatial autocorrelation. The simulation study shows excellent recovery of the model parameters and demonstrates the consequences…

  10. Analysis of Risk Factors for Postoperative Morbidity in Perforated Peptic Ulcer

    PubMed Central

    Kim, Jae-Myung; Jeong, Sang-Ho; Park, Soon-Tae; Choi, Sang-Kyung; Hong, Soon-Chan; Jung, Eun-Jung; Ju, Young-Tae; Jeong, Chi-Young; Ha, Woo-Song

    2012-01-01

    Purpose Emergency operations for perforated peptic ulcer are associated with a high incidence of postoperative complications. While several studies have investigated the impact of perioperative risk factors and underlying diseases on the postoperative morbidity after abdominal surgery, only a few have analyzed their role in perforated peptic ulcer disease. The purpose of this study was to determine any possible associations between postoperative morbidity and comorbid disease or perioperative risk factors in perforated peptic ulcer. Materials and Methods In total, 142 consecutive patients, who underwent surgery for perforated peptic ulcer, at a single institution, between January 2005 and October 2010 were included in this study. The clinical data concerning the patient characteristics, operative methods, and complications were collected retrospectively. Results The postoperative morbidity rate associated with perforated peptic ulcer operations was 36.6% (52/142). Univariate analysis revealed that a long operating time, the open surgical method, age (≥60), sex (female), high American Society of Anesthesiologists (ASA) score and presence of preoperative shock were significant perioperative risk factors for postoperative morbidity. Significant comorbid risk factors included hypertension, diabetes mellitus and pulmonary disease. Multivariate analysis revealed a long operating time, the open surgical method, high ASA score and the presence of preoperative shock were all independent risk factors for the postoperative morbidity in perforated peptic ulcer. Conclusions A high ASA score, preoperative shock, open surgery and long operating time of more than 150 minutes are high risk factors for morbidity. However, there is no association between postoperative morbidity and comorbid disease in patients with a perforated peptic ulcer. PMID:22500261

  11. Analysis of risk factors for postoperative morbidity in perforated peptic ulcer.

    PubMed

    Kim, Jae-Myung; Jeong, Sang-Ho; Lee, Young-Joon; Park, Soon-Tae; Choi, Sang-Kyung; Hong, Soon-Chan; Jung, Eun-Jung; Ju, Young-Tae; Jeong, Chi-Young; Ha, Woo-Song

    2012-03-01

    Emergency operations for perforated peptic ulcer are associated with a high incidence of postoperative complications. While several studies have investigated the impact of perioperative risk factors and underlying diseases on the postoperative morbidity after abdominal surgery, only a few have analyzed their role in perforated peptic ulcer disease. The purpose of this study was to determine any possible associations between postoperative morbidity and comorbid disease or perioperative risk factors in perforated peptic ulcer. In total, 142 consecutive patients, who underwent surgery for perforated peptic ulcer, at a single institution, between January 2005 and October 2010 were included in this study. The clinical data concerning the patient characteristics, operative methods, and complications were collected retrospectively. The postoperative morbidity rate associated with perforated peptic ulcer operations was 36.6% (52/142). Univariate analysis revealed that a long operating time, the open surgical method, age (≥60), sex (female), high American Society of Anesthesiologists (ASA) score and presence of preoperative shock were significant perioperative risk factors for postoperative morbidity. Significant comorbid risk factors included hypertension, diabetes mellitus and pulmonary disease. Multivariate analysis revealed a long operating time, the open surgical method, high ASA score and the presence of preoperative shock were all independent risk factors for the postoperative morbidity in perforated peptic ulcer. A high ASA score, preoperative shock, open surgery and long operating time of more than 150 minutes are high risk factors for morbidity. However, there is no association between postoperative morbidity and comorbid disease in patients with a perforated peptic ulcer.

  12. Research on the relationship between the elements and pharmacological activities in velvet antler using factor analysis and cluster analysis

    NASA Astrophysics Data System (ADS)

    Zhou, Libing

    2017-04-01

    Velvet antler has certain effect on improving the body's immune cells and the regulation of immune system function, nervous system, anti-stress, anti-aging and osteoporosis. It has medicinal applications to treat a wide range of diseases such as tissue wound healing, anti-tumor, cardiovascular disease, et al. Therefore, the research on the relationship between pharmacological activities and elements in velvet antler is of great significance. The objective of this study was to comprehensively evaluate 15 kinds of elements in different varieties of velvet antlers and study on the relationship between the elements and traditional Chinese medicine efficacy for the human. The factor analysis and the factor cluster analysis methods were used to analyze the data of elements in the sika velvet antler, cervus elaphus linnaeus, flower horse hybrid velvet antler, apiti (elk) velvet antler, male reindeer velvet antler and find out the relationship between 15 kinds of elements including Ca, P, Mg, Na, K, Fe, Cu, Mn, Al, Ba, Co, Sr, Cr, Zn and Ni. Combining with MATLAB2010 and SPSS software, the chemometrics methods were made on the relationship between the elements in velvet antler and the pharmacological activities. The first commonality factor F1 had greater load on the indexes of Ca, P, Mg, Co, Sr and Ni, and the second commonality factor F2 had greater load on the indexes of K, Mn, Zn and Cr, and the third commonality factor F3 had greater load on the indexes of Na, Cu and Ba, and the fourth commonality factor F4 had greater load on the indexes of Fe and Al. 15 kinds of elements in velvet antler in the order were elk velvet antler>flower horse hybrid velvet antler>cervus elaphus linnaeus>sika velvet antler>male reindeer velvet antler. Based on the factor analysis and the factor cluster analysis, a model for evaluating traditional Chinese medicine quality was constructed. These studies provide the scientific base and theoretical foundation for the future large-scale rational

  13. On the stability analysis of approximate factorization methods for 3D Euler and Navier-Stokes equations

    NASA Technical Reports Server (NTRS)

    Demuren, A. O.; Ibraheem, S. O.

    1993-01-01

    The convergence characteristics of various approximate factorizations for the 3D Euler and Navier-Stokes equations are examined using the von-Neumann stability analysis method. Three upwind-difference based factorizations and several central-difference based factorizations are considered for the Euler equations. In the upwind factorizations both the flux-vector splitting methods of Steger and Warming and van Leer are considered. Analysis of the Navier-Stokes equations is performed only on the Beam and Warming central-difference scheme. The range of CFL numbers over which each factorization is stable is presented for one-, two-, and three-dimensional flow. Also presented for each factorization is the CFL number at which the maximum eigenvalue is minimized, for all Fourier components, as well as for the high frequency range only. The latter is useful for predicting the effectiveness of multigrid procedures with these schemes as smoothers. Further, local mode analysis is performed to test the suitability of using a uniform flow field in the stability analysis. Some inconsistencies in the results from previous analyses are resolved.

  14. Memory systems, processes, and tasks: taxonomic clarification via factor analysis.

    PubMed

    Bruss, Peter J; Mitchell, David B

    2009-01-01

    The nature of various memory systems was examined using factor analysis. We reanalyzed data from 11 memory tasks previously reported in Mitchell and Bruss (2003). Four well-defined factors emerged, closely resembling episodic and semantic memory and conceptual and perceptual implicit memory, in line with both memory systems and transfer-appropriate processing accounts. To explore taxonomic issues, we ran separate analyses on the implicit tasks. Using a cross-format manipulation (pictures vs. words), we identified 3 prototypical tasks. Word fragment completion and picture fragment identification tasks were "factor pure," tapping perceptual processes uniquely. Category exemplar generation revealed its conceptual nature, yielding both cross-format priming and a picture superiority effect. In contrast, word stem completion and picture naming were more complex, revealing attributes of both processes.

  15. Factor Analysis of Drawings: Application to college student models of the greenhouse effect

    NASA Astrophysics Data System (ADS)

    Libarkin, Julie C.; Thomas, Stephen R.; Ording, Gabriel

    2015-09-01

    Exploratory factor analysis was used to identify models underlying drawings of the greenhouse effect made by over 200 entering university freshmen. Initial content analysis allowed deconstruction of drawings into salient features, with grouping of these features via factor analysis. A resulting 4-factor solution explains 62% of the data variance, suggesting that 4 archetype models of the greenhouse effect dominate thinking within this population. Factor scores, indicating the extent to which each student's drawing aligned with representative models, were compared to performance on conceptual understanding and attitudes measures, demographics, and non-cognitive features of drawings. Student drawings were also compared to drawings made by scientists to ascertain the extent to which models reflect more sophisticated and accurate models. Results indicate that student and scientist drawings share some similarities, most notably the presence of some features of the most sophisticated non-scientific model held among the study population. Prior knowledge, prior attitudes, gender, and non-cognitive components are also predictive of an individual student's model. This work presents a new technique for analyzing drawings, with general implications for the use of drawings in investigating student conceptions.

  16. Analysis of Factors Related to Hypopituitarism in Patients with Nonsellar Intracranial Tumor.

    PubMed

    Lu, Song-Song; Gu, Jian-Jun; Luo, Xiao-Hong; Zhang, Jian-He; Wang, Shou-Sen

    2017-09-01

    Previous studies have suggested that postoperative hypopituitarism in patients with nonsellar intracranial tumors is caused by traumatic surgery. However, with development of minimally invasive and precise neurosurgical techniques, the degree of injury to brain tissue has been reduced significantly, especially for parenchymal tumors. Therefore, understanding preexisting hypopituitarism and related risk factors can improve perioperative management for patients with nonsellar intracranial tumors. Chart data were collected retrospectively from 83 patients with nonsellar intracranial tumors admitted to our hospital from May 2014 to April 2015. Pituitary function of each subject was determined based on results of preoperative serum pituitary hormone analysis. Univariate and multivariate logistic regression methods were used to analyze relationships between preoperative hypopituitarism and factors including age, sex, history of hypertension and secondary epilepsy, course of disease, tumor mass effect, site of tumor, intracranial pressure (ICP), cerebrospinal fluid content, and pituitary morphology. A total of 30 patients (36.14%) presented with preoperative hypopituitarism in either 1 axis or multiple axes; 23 (27.71%) were affected in 1 axis, and 7 (8.43%) were affected in multiple axes. Univariate analysis showed that risk factors for preoperative hypopituitarism in patients with a nonsellar intracranial tumor include an acute or subacute course (≤3 months), intracranial hypertension (ICP >200 mm H 2 O), and mass effect (P < 0.05). Multivariate logistic regression analysis showed that mass effect is an independent risk factor for preoperative hypopituitarism in patients with nonsellar intracranial tumors (P < 0.05; odds ratio, 3.197). Prevalence of hypopituitarism is high in patients with nonsellar intracranial tumors. The occurrence of hypopituitarism is correlated with factors including an acute or subacute course (≤3 months), intracranial hypertension (ICP >200

  17. Exploratory factor analysis of the Clinical Learning Environment, Supervision and Nurse Teacher Scale (CLES+T).

    PubMed

    Watson, Paul Barry; Seaton, Philippa; Sims, Deborah; Jamieson, Isabel; Mountier, Jane; Whittle, Rose; Saarikoski, Mikko

    2014-01-01

    The Clinical Learning Environment, Supervision and Nurse Teacher (CLES+T) scale measures student nurses' perceptions of clinical learning environments. This study evaluates the construct validity and internal reliability of the CLES+T in hospital settings in New Zealand. Comparisons are made between New Zealand and Finnish data. The CLES+T scale was completed by 416 Bachelor of Nursing students following hospital clinical placements between October 2008 and December 2009. Construct validity and internal reliability were assessed using exploratory factor analysis and Cronbach's alpha. Exploratory factor analysis supports 4 factors. Cronbach's alpha ranged from .82 to .93. All items except 1 loaded on the same factors found in unpublished Finnish data. The first factor combined 2 previous components from the published Finnish component analysis and was renamed: connecting with, and learning in, communities of clinical practice. The remaining 3 factors (Nurse teacher, Supervisory relationship, and Leadership style of the manager) corresponded to previous components and their conceptualizations. The CLES+T has good internal reliability and a consistent factor structure across samples. The consistency across international samples supports faculties and hospitals using the CLES+T to benchmark the quality of clinical learning environments provided to students.

  18. Factor Rotation and Standard Errors in Exploratory Factor Analysis

    ERIC Educational Resources Information Center

    Zhang, Guangjian; Preacher, Kristopher J.

    2015-01-01

    In this article, we report a surprising phenomenon: Oblique CF-varimax and oblique CF-quartimax rotation produced similar point estimates for rotated factor loadings and factor correlations but different standard error estimates in an empirical example. Influences of factor rotation on asymptotic standard errors are investigated using a numerical…

  19. Analysis of functional redundancies within the Arabidopsis TCP transcription factor family.

    PubMed

    Danisman, Selahattin; van Dijk, Aalt D J; Bimbo, Andrea; van der Wal, Froukje; Hennig, Lars; de Folter, Stefan; Angenent, Gerco C; Immink, Richard G H

    2013-12-01

    Analyses of the functions of TEOSINTE-LIKE1, CYCLOIDEA, and PROLIFERATING CELL FACTOR1 (TCP) transcription factors have been hampered by functional redundancy between its individual members. In general, putative functionally redundant genes are predicted based on sequence similarity and confirmed by genetic analysis. In the TCP family, however, identification is impeded by relatively low overall sequence similarity. In a search for functionally redundant TCP pairs that control Arabidopsis leaf development, this work performed an integrative bioinformatics analysis, combining protein sequence similarities, gene expression data, and results of pair-wise protein-protein interaction studies for the 24 members of the Arabidopsis TCP transcription factor family. For this, the work completed any lacking gene expression and protein-protein interaction data experimentally and then performed a comprehensive prediction of potential functional redundant TCP pairs. Subsequently, redundant functions could be confirmed for selected predicted TCP pairs by genetic and molecular analyses. It is demonstrated that the previously uncharacterized class I TCP19 gene plays a role in the control of leaf senescence in a redundant fashion with TCP20. Altogether, this work shows the power of combining classical genetic and molecular approaches with bioinformatics predictions to unravel functional redundancies in the TCP transcription factor family.

  20. Analysis of functional redundancies within the Arabidopsis TCP transcription factor family

    PubMed Central

    Danisman, Selahattin; de Folter, Stefan; Immink, Richard G. H.

    2013-01-01

    Analyses of the functions of TEOSINTE-LIKE1, CYCLOIDEA, and PROLIFERATING CELL FACTOR1 (TCP) transcription factors have been hampered by functional redundancy between its individual members. In general, putative functionally redundant genes are predicted based on sequence similarity and confirmed by genetic analysis. In the TCP family, however, identification is impeded by relatively low overall sequence similarity. In a search for functionally redundant TCP pairs that control Arabidopsis leaf development, this work performed an integrative bioinformatics analysis, combining protein sequence similarities, gene expression data, and results of pair-wise protein–protein interaction studies for the 24 members of the Arabidopsis TCP transcription factor family. For this, the work completed any lacking gene expression and protein–protein interaction data experimentally and then performed a comprehensive prediction of potential functional redundant TCP pairs. Subsequently, redundant functions could be confirmed for selected predicted TCP pairs by genetic and molecular analyses. It is demonstrated that the previously uncharacterized class I TCP19 gene plays a role in the control of leaf senescence in a redundant fashion with TCP20. Altogether, this work shows the power of combining classical genetic and molecular approaches with bioinformatics predictions to unravel functional redundancies in the TCP transcription factor family. PMID:24129704

  1. Impact of a pneumatic tube system transport on hemostasis parameters measurement: the experiment of Cochin universitary hospital (AP-HP, Paris, France).

    PubMed

    Calmette, Leyla; Ibrahim, Firas; Gouin, Isabelle; Horellou, Marie-Hélène; Mazoyer, Élisabeth; Fontenay, Michaela; Flaujac, Claire

    2017-02-01

    Samples transported by pneumatic tube system are submitted to forces of acceleration and deceleration which can affect laboratory parameters. At Cochin hospital, majority of samples of hemostasis, except for platelets tests, are transported by pneumatic tube system. The objective of this study was to evaluate the impact of a pneumatic tube system (PTS) transport compared to hand-delivered transport on samples and to qualify Cochin hospital PTS according to requirements of standard ISO 15189. A bibliographical study was made and showed that pneumatic tube system particularly influences platelets tests. Four citrate tubes were collected in 5 healthy volunteers in the maternity: 2 tubes were transported by PTS and 2 others were hand-delivered to the laboratory. Five coagulation tests were analyzed: prothrombine time (PT), activated partial thromboplastin time (aPTT), factor (F) V, FVIII and platelet closure time with PFA-100TM collagen/epinephrine. For each volunteer, the results obtained by PTS and by hand-delivered transport were compared with formula usually used for biological analysis retake: 2.8 x standard deviation of reproductibility variation coefficient (SH GTA 01, COFRAC). This study did not show an impact of PTS on PT, aPTT, FV and FVIII. For PFA-100TM collagen/epinephrine, we noted an impact on 2/5 volunteers. These results, in agreement with the literature, led to the conclusion that Cochin hospital PTS is in compliance to transport samples for usual coagulation tests except platelet tests. This study allowed to issue French recommendations for PTS transport of hemostasis tubes qualification available on "Groupe français d'hémostase et thrombose" Web site.

  2. Cancer risk factors in Korean news media: a content analysis.

    PubMed

    Kye, Su Yeon; Kwon, Jeong Hyun; Kim, Yong-Chan; Shim, Minsun; Kim, Jee Hyun; Cho, Hyunsoon; Jung, Kyu Won; Park, Keeho

    2015-01-01

    Little is known about the news coverage of cancer risk factors in Korea. This study aimed to examine how the news media encompasses a wide array of content regarding cancer risk factors and related cancer sites, and investigate whether news coverage of cancer risk factors is congruent with the actual prevalence of the disease. A content analysis was conducted on 1,138 news stories covered during a 5-year period between 2008 and 2012. The news stories were selected from nationally representative media in Korea. Information was collected about cancer risk factors and cancer sites. Of various cancer risk factors, occupational and environmental exposures appeared most frequently in the news. Breast cancer was mentioned the most in relation to cancer sites. Breast, cervical, prostate, and skin cancer were overrepresented in the media in comparison to incidence and mortality cases, whereas lung, thyroid, liver, and stomach cancer were underrepresented. To our knowledge, this research is the first investigation dealing with news coverage about cancer risk factors in Korea. The study findings show occupational and environmental exposures are emphasized more than personal lifestyle factors; further, more prevalent cancers in developed countries have greater media coverage, not reflecting the realities of the disease. The findings may help health journalists and other health storytellers to develop effective ways to communicate cancer risk factors.

  3. [Habitat factor analysis for Torreya grandis cv. Merrillii based on spatial information technology].

    PubMed

    Wang, Xiao-ming; Wang, Ke; Ao, Wei-jiu; Deng, Jin-song; Han, Ning; Zhu, Xiao-yun

    2008-11-01

    Torreya grandis cv. Merrillii, a tertiary survival plant, is a rare tree species of significant economic value and expands rapidly in China. Its special habitat factor analysis has the potential value to provide guide information for its planting, management, and sustainable development, because the suitable growth conditions for this tree species are special and strict. In this paper, the special habitat factors for T. grandis cv. Merrillii in its core region, i.e., in seven villages of Zhuji City, Zhejiang Province were analyzed with Principal Component Analysis (PCA) and a series of data, such as IKONOS image, Digital Elevation Model (DEM), and field survey data supported by the spatial information technology. The results showed that T. grandis cv. Merrillii exhibited high selectivity of environmental factors such as elevation, slope, and aspect. 96.22% of T. grandis cv. Merrillii trees were located at the elevation from 300 to 600 m, 97.52% of them were found to present on the areas whose slope was less than 300, and 74.43% of them distributed on sunny and half-sunny slopes. The results of PCA analysis indicated that the main environmental factors affecting the habitat of T. grandis cv. Merrillii were moisture, heat, and soil nutrients, and moisture might be one of the most important ecological factors for T. grandis cv. Merrillii due to the unique biological and ecological characteristics of the tree species.

  4. The Prediction-Focused Approach: An opportunity for hydrogeophysical data integration and interpretation

    NASA Astrophysics Data System (ADS)

    Hermans, Thomas; Nguyen, Frédéric; Klepikova, Maria; Dassargues, Alain; Caers, Jef

    2017-04-01

    and hydrological data are combined to derive a direct relationship between data and forecast. We illustrate the process for the design of an aquifer thermal energy storage (ATES) system. An ATES system can theoretically recover in winter the heat stored in the aquifer during summer. In practice, the energy efficiency is often lower than expected due to spatial heterogeneity of hydraulic properties combined to a non-favorable hydrogeological gradient. A proper design of ATES systems should consider the uncertainty of the prediction related to those parameters. With a global sensitivity analysis, we identify sensitive parameters for heat storage prediction and validate the use of a short term heat tracing experiment monitored with geophysics to generate informative data. First, we illustrate how PFA can be used to successfully derive the distribution of temperature in the aquifer from ERT during the heat tracing experiment. Then, we successfully integrate the geophysical data to predict medium-term heat storage in the aquifer using PFA. The result is a full quantification of the posterior distribution of the prediction conditioned to observed data in a relatively limited time budget.

  5. Risk factors in laparoscopic cholecystectomy: a multivariate analysis.

    PubMed

    Kanakala, Venkatesh; Borowski, David W; Pellen, Michael G C; Dronamraju, Shridhar S; Woodcock, Sean A A; Seymour, Keith; Attwood, Stephen E A; Horgan, Liam F

    2011-01-01

    Laparoscopic cholecystectomy (LC) is the operation of choice in the treatment of symptomatic gallstone disease. The aim of this study is to identify risk factors for LC, outcomes include operating time, length of stay, conversion rate, morbidity and mortality. All patients undergoing LC between 1998 and 2007 in a single district general hospital. Risk factors were examined using uni- and multivariate analysis. 2117 patients underwent LC, with 1706 (80.6%) patients operated on electively. Male patients were older, had more co-morbidity and more emergency surgery than females. The median post-operative hospital stay was one day, and was positively correlated with the complexity of surgery. Conversion rates were higher in male patients (OR 1.47, p = 0.047) than in females, and increased with co-morbidity. Emergency surgery (OR 1.75, p = 0.005), male gender (OR 1.68, p = 0.005), increasing co-morbidity and complexity of surgery were all positively associated with the incidence of complications (153/2117 [7.2%]), whereas only male gender was significantly associated with mortality (OR 5.71, p = 0.025). Adverse outcome from LC is particularly associated with male gender, but also the patient's co-morbidity, complexity and urgency of surgery. Risk-adjusted outcome analysis is desirable to ensure an informed consent process. Copyright © 2011 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

  6. FACTOR ANALYSIS OF A SOCIAL SKILLS SCALE FOR HIGH SCHOOL STUDENTS.

    PubMed

    Wang, H-Y; Lin, C-K

    2015-10-01

    The objective of this study was to develop a social skills scale for high school students in Taiwan. This study adopted stratified random sampling. A total of 1,729 high school students were included. The students ranged in age from 16 to 18 years. A Social Skills Scale was developed for this study and was designed for classroom teachers to fill out. The test-retest reliability of this scale was tested by Pearson's correlation coefficient. Exploratory factor analysis was used to determine construct validity. The Social Skills Scale had good overall test-retest reliability of .92, and the internal consistency of the five subscales was above .90. The results of the factor analysis showed that the Social Skills Scale covered the five domains of classroom learning skills, communication skills, individual initiative skills, interaction skills, and job-related social skills, and the five factors explained 68.34% of the variance. Thus, the Social Skills Scale had good reliability and validity and would be applicable to and could be promoted for use in schools.

  7. The power flow angle of acoustic waves in thin piezoelectric plates.

    PubMed

    Kuznetsova, Iren E; Zaitsev, Boris D; Teplykh, Andrei A; Joshi, Shrinivas G; Kuznetsova, Anastasia S

    2008-09-01

    The curves of slowness and power flow angle (PFA) of quasi-antisymmetric (A(0)) and quasi-symmetric (S(0)) Lamb waves as well as quasi-shear-horizontal (SH(0)) acoustic waves in thin plates of lithium niobate and potassium niobate of X-,Y-, and Z-cuts for various propagation directions and the influence of electrical shorting of one plate surface on these curves and PFA have been theoretically investigated. It has been found that the group velocity of such waves does not coincide with the phase velocity for the most directions of propagation. It has been also shown that S(0) and SH(0) wave are characterized by record high values of PFA and its change due to electrical shorting of the plate surface in comparison with surface and bulk acoustic waves in the same material. The most interesting results have been verified by experiment. As a whole, the results obtained may be useful for development of various devices for signal processing, for example, electrically controlled acoustic switchers.

  8. Evaluating the Mobility of Arsenic in Synthetic Iron-containing Solids Using a Modified Sequential Extraction Method

    PubMed Central

    Shan, Jilei; Sáez, A. Eduardo; Ela, Wendell P.

    2013-01-01

    Many water treatment technologies for arsenic removal that are used today produce arsenic-bearing residuals which are disposed in non-hazardous landfills. Previous works have established that many of these residuals will release arsenic to a much greater extent than predicted by standard regulatory leaching tests (e.g. the toxicity characteristic leaching procedure, TCLP) and, consequently, require stabilization to ensure benign behavior after disposal. In this work, a four-step sequential extraction method was developed in an effort to determine the proportion of arsenic in various phases in untreated as well as stabilized iron-based solid matrices. The solids synthesized using various potential stabilization techniques included: amorphous arsenic-iron sludge (ASL), reduced ASL via reaction with zero valent iron (RASL), amorphous ferrous arsenate (PFA), a mixture of PFA and SL (M1), crystalline ferrous arsenate (HPFA), and a mixture of HPFA and SL (M2). The overall arsenic mobility of the tested samples increased in the following order: ASL > RASL > PFA > M1 > HPFA > M2. PMID:23459695

  9. [Mathematic analysis of risk factors influence on occupational respiratory diseases development].

    PubMed

    Budkar', L N; Bugaeva, I V; Obukhova, T Iu; Tereshina, L G; Karpova, E A; Shmonina, O G

    2010-01-01

    Analysis covered 1348 case histories of workers exposed to industrial dust in Urals region. The analysis applied mathematical processing of survival theory and correlation analysis. The authors studied influence of various factors: dust concentration, connective tissue dysplasia, smoking habits--on duration for diseases caused by dust to appear. Findings are that occupational diseases develop reliably faster with higher ambient dust concentrations and with connective tissue dysplasia syndrome. Smoking habits do not alter duration of pneumoconiosis development, but reliably increases development of occupational dust bronchitis.

  10. Factor analysis and predictive validity of microcomputer-based tests

    NASA Technical Reports Server (NTRS)

    Kennedy, R. S.; Baltzley, D. R.; Turnage, J. J.; Jones, M. B.

    1989-01-01

    11 tests were selected from two microcomputer-based performance test batteries because previously these tests exhibited rapid stability (less than 10 min, of practice) and high retest reliability efficiencies (r greater than 0.707 for each 3 min. of testing). The battery was administered three times to each of 108 college students (48 men and 60 women) and a factor analysis was performed. Two of the three identified factors appear to be related to information processing ("encoding" and "throughput/decoding"), and the third named an "output/speed" factor. The spatial, memory, and verbal tests loaded on the "encoding" factor and included Grammatical Reasoning, Pattern Comparison, Continuous Recall, and Matrix Rotation. The "throughput/decoding" tests included perceptual/numerical tests like Math Processing, Code Substitution, and Pattern Comparison. The output speed factor was identified by Tapping and Reaction Time tests. The Wonderlic Personnel Test was group administered before the first and after the last administration of the performance tests. The multiple Rs in the total sample between combined Wonderlic as a criterion and less than 5 min. of microcomputer testing on Grammatical Reasoning and Math Processing as predictors ranged between 0.41 and 0.52 on the three test administrations. Based on these results, the authors recommend a core battery which, if time permits, would consist of two tests from each factor. Such a battery is now known to permit stable, reliable, and efficient assessment.

  11. A Meta-Analysis on the Factors That Best Reduce the Achievement Gap

    ERIC Educational Resources Information Center

    Jeynes, William H.

    2015-01-01

    A meta-analyses was undertaken to determine the factors that are most related with reducing the achievement gap. The meta-analysis included 30 studies that examined attempts to bridge the achievement gap between White students on one hand and Black and Latino students on the other. The results indicate that several factors are associated with a…

  12. Human error analysis of commercial aviation accidents using the human factors analysis and classification system (HFACS)

    DOT National Transportation Integrated Search

    2001-02-01

    The Human Factors Analysis and Classification System (HFACS) is a general human error framework : originally developed and tested within the U.S. military as a tool for investigating and analyzing the human : causes of aviation accidents. Based upon ...

  13. [Analysis on influencing factors of prognosis of patients with acute organophosphorus pesticide poisoning].

    PubMed

    Guo, C F; Wang, Y; Liu, J H; Shen, P; Wang, H; Wei, Y J; Shi, X F; Zhou, X J; Wang, W W

    2016-05-20

    To analyze the relationship between risk factors and prognosis of acute organophosphorus pesticide poisoning (AOPP). The clinical data including APACHEⅡ, D-dimer, C-reactive protein, procalcitonin, lactic acid of the 67 cases of acute organophosphorus pesticide poisoning which respectively divided into survival group and death group by the outcome were collected. The independent influcing factors were got by logistic regression analysis. The analysis showed that APACHEⅡ, D-dimer、C-reactive protein and Procalcitonin were influencing factors to evaluate prognosis of AOPP (P<0.05) .Meanwhile, APACHEⅡ and CRP were the independent influencing factors to evaluate prognosis of AOPP (P<0.05). APACHEⅡ26was the optimum thresholds to acess the prognosis of AOPP and its Youden index was largest. APACHEⅡ and CRP played an important role in the assessment of prognosis on AOPP. When APACHEⅡwas more than 26, it suggested the patient of AOPP will have a bad prognosis.

  14. A computational intelligent approach to multi-factor analysis of violent crime information system

    NASA Astrophysics Data System (ADS)

    Liu, Hongbo; Yang, Chao; Zhang, Meng; McLoone, Seán; Sun, Yeqing

    2017-02-01

    Various scientific studies have explored the causes of violent behaviour from different perspectives, with psychological tests, in particular, applied to the analysis of crime factors. The relationship between bi-factors has also been extensively studied including the link between age and crime. In reality, many factors interact to contribute to criminal behaviour and as such there is a need to have a greater level of insight into its complex nature. In this article we analyse violent crime information systems containing data on psychological, environmental and genetic factors. Our approach combines elements of rough set theory with fuzzy logic and particle swarm optimisation to yield an algorithm and methodology that can effectively extract multi-knowledge from information systems. The experimental results show that our approach outperforms alternative genetic algorithm and dynamic reduct-based techniques for reduct identification and has the added advantage of identifying multiple reducts and hence multi-knowledge (rules). Identified rules are consistent with classical statistical analysis of violent crime data and also reveal new insights into the interaction between several factors. As such, the results are helpful in improving our understanding of the factors contributing to violent crime and in highlighting the existence of hidden and intangible relationships between crime factors.

  15. Factor analysis and cluster analysis applied to assess the water quality of middle and lower Han River in Central China

    NASA Astrophysics Data System (ADS)

    Kuo, Yi-Ming; Liu, Wen-Wen

    2015-04-01

    The Han River basin is one of the most important industrial and grain production bases in the central China. A lot of factories and towns have been established along the river where large farmlands are located nearby. In the last few decades the water quality of the Han River, specifically in middle and lower reaches, has gradually declined. The agricultural nonpoint pollution and municipal and industrial point pollution significantly degrade the water quality of the Han River. Factor analysis can be applied to reduce the dimensionality of a data set consisting of a large number of inter-related variables. Cluster analysis can classify the samples according to their similar characters. In this study, factor analysis is used to identify major pollution indicators, and cluster analysis is employed to classify the samples based on the sample locations and hydrochemical variables. Water samples were collected from 12 sample sites collected from Xiangyang City (middle Han River) to Wuhan City (lower Han River). Correlations among 25 hydrochemical variables are statistically examined. The important pollutants are determined by factor analysis. A three-factor model is determined and explains over 85% of the total river water quality variation. Factor 1, including SS, Chl-a, TN and TP, can be considered as the nonpoint source pollution. Factor 2, including Cl-, Br-, SO42-, Ca2+, Mg2+, K+, Fe2+ and PO43-, can be treated as the industrial pollutant pollution. Factor 3, including F- and NO3-, reflects the influence of the groundwater or self-purification capability of the river water. The various land uses along the Han River correlate well with the pollution types. In addition, the result showed that the water quality of Han River deteriorated gradually from middle to lower Han River. Some tributaries have been seriously polluted and significantly influence the mainstream water quality of the Han River. Finally, the result showed that the nonpoint pollution and the point

  16. Factors influencing societal response of nanotechnology: an expert stakeholder analysis

    NASA Astrophysics Data System (ADS)

    Gupta, Nidhi; Fischer, Arnout R. H.; van der Lans, Ivo A.; Frewer, Lynn J.

    2012-05-01

    Nanotechnology can be described as an emerging technology and, as has been the case with other emerging technologies such as genetic modification, different socio-psychological factors will potentially influence societal responses to its development and application. These factors will play an important role in how nanotechnology is developed and commercialised. This article aims to identify expert opinion on factors influencing societal response to applications of nanotechnology. Structured interviews with experts on nanotechnology from North West Europe were conducted using repertory grid methodology in conjunction with generalized Procrustes analysis to examine the psychological constructs underlying societal uptake of 15 key applications of nanotechnology drawn from different areas (e.g. medicine, agriculture and environment, chemical, food, military, sports, and cosmetics). Based on expert judgement, the main factors influencing societal response to different applications of nanotechnology will be the extent to which applications are perceived to be beneficial, useful, and necessary, and how 'real' and physically close to the end-user these applications are perceived to be by the public.

  17. Emotional Intelligence and Nurse Recruitment: Rasch and confirmatory factor analysis of the trait emotional intelligence questionnaire short form.

    PubMed

    Snowden, Austyn; Watson, Roger; Stenhouse, Rosie; Hale, Claire

    2015-12-01

    To examine the construct validity of the Trait Emotional Intelligence Questionnaire Short form. Emotional intelligence involves the identification and regulation of our own emotions and the emotions of others. It is therefore a potentially useful construct in the investigation of recruitment and retention in nursing and many questionnaires have been constructed to measure it. Secondary analysis of existing dataset of responses to Trait Emotional Intelligence Questionnaire Short form using concurrent application of Rasch analysis and confirmatory factor analysis. First year undergraduate nursing and computing students completed Trait Emotional Intelligence Questionnaire-Short Form in September 2013. Responses were analysed by synthesising results of Rasch analysis and confirmatory factor analysis. Participants (N = 938) completed Trait Emotional Intelligence Questionnaire Short form. Rasch analysis showed the majority of the Trait Emotional Intelligence Questionnaire-Short Form items made a unique contribution to the latent trait of emotional intelligence. Five items did not fit the model and differential item functioning (gender) accounted for this misfit. Confirmatory factor analysis revealed a four-factor structure consisting of: self-confidence, empathy, uncertainty and social connection. All five misfitting items from the Rasch analysis belonged to the 'social connection' factor. The concurrent use of Rasch and factor analysis allowed for novel interpretation of Trait Emotional Intelligence Questionnaire Short form. Much of the response variation in Trait Emotional Intelligence Questionnaire Short form can be accounted for by the social connection factor. Implications for practice are discussed. © 2015 John Wiley & Sons Ltd.

  18. Patients with metabolic syndrome exhibit higher platelet activity than those with conventional risk factors for vascular disease.

    PubMed

    Serebruany, Victor L; Malinin, Alex; Ong, Stephen; Atar, Dan

    2008-04-01

    The metabolic syndrome is a matter of ongoing debate with regard to its existence, classification, clinical meaningfulness, and associated risks for vessel occlusion. Considering that persistent platelet activation is a cornerstone for the development of acute vascular events, and that patients with type 2 diabetes consistently exhibit high platelet activity, these characteristics may be critical for distinguishing and triageing specific features of metabolic syndrome among established risk factors for vascular disease. We assessed the platelet activity by conventional aggregation, expression of major surface receptors by flow cytometry, and quantitatively by rapid bedside analyzers in 20 aspirin-naïve patients with documented metabolic syndrome, and compared these with 20 untreated subjects with multiple cardiovascular risk factors. Closure time by the PFA-100 analyzer was significantly (P = 0.002) shorter in patients with metabolic syndrome indicating platelet inhibition under high shear conditions. Ultegra analyzer readings revealed increased fibrinogen binding (P = 0.0003) what in combination with the increased expression of PAC-1 (P = 0.32) strongly suggest activation of platelet glycoprotein IIb/IIIa receptor. Surface expression of CD107a (P = 0.014), and SPAN-12 (P = 0.003) were also higher in patients with metabolic syndrome. In contrast, platelet aggregation induced by collagen or ADP, CD31, CD41, CD42b, CD51/61, CD62p, CD63, CD154, CD165, so as formation of platelet-monocyte aggregates, PAR-1 thrombin receptor, and thrombospondin did not differ between groups. Patients with metabolic syndrome exhibited a higher degree of platelet activation than subjects with conventional risk factors for vascular disease. Conceptually, applying adequate antiplatelet strategies may reduce the risk of acute thrombotic events in these patients. Further prospective studies exploring this notion are encouraged.

  19. Cement Leakage in Percutaneous Vertebral Augmentation for Osteoporotic Vertebral Compression Fractures: Analysis of Risk Factors.

    PubMed

    Xie, Weixing; Jin, Daxiang; Ma, Hui; Ding, Jinyong; Xu, Jixi; Zhang, Shuncong; Liang, De

    2016-05-01

    The risk factors for cement leakage were retrospectively reviewed in 192 patients who underwent percutaneous vertebral augmentation (PVA). To discuss the factors related to the cement leakage in PVA procedure for the treatment of osteoporotic vertebral compression fractures. PVA is widely applied for the treatment of osteoporotic vertebral fractures. Cement leakage is a major complication of this procedure. The risk factors for cement leakage were controversial. A retrospective review of 192 patients who underwent PVA was conducted. The following data were recorded: age, sex, bone density, number of fractured vertebrae before surgery, number of treated vertebrae, severity of the treated vertebrae, operative approach, volume of injected bone cement, preoperative vertebral compression ratio, preoperative local kyphosis angle, intraosseous clefts, preoperative vertebral cortical bone defect, and ratio and type of cement leakage. To study the correlation between each factor and cement leakage ratio, bivariate regression analysis was employed to perform univariate analysis, whereas multivariate linear regression analysis was employed to perform multivariate analysis. The study included 192 patients (282 treated vertebrae), and cement leakage occurred in 100 vertebrae (35.46%). The vertebrae with preoperative cortical bone defects generally exhibited higher cement leakage ratio, and the leakage is typically type C. Vertebrae with intact cortical bones before the procedure tend to experience type S leakage. Univariate analysis showed that patient age, bone density, number of fractured vertebrae before surgery, and vertebral cortical bone were associated with cement leakage ratio (P<0.05). Multivariate analysis showed that the main factors influencing bone cement leakage are bone density and vertebral cortical bone defect, with standardized partial regression coefficients of -0.085 and 0.144, respectively. High bone density and vertebral cortical bone defect are

  20. The correct estimate of the probability of false detection of the matched filter in weak-signal detection problems . II. Further results with application to a set of ALMA and ATCA data

    NASA Astrophysics Data System (ADS)

    Vio, R.; Vergès, C.; Andreani, P.

    2017-08-01

    The matched filter (MF) is one of the most popular and reliable techniques to the detect signals of known structure and amplitude smaller than the level of the contaminating noise. Under the assumption of stationary Gaussian noise, MF maximizes the probability of detection subject to a constant probability of false detection or false alarm (PFA). This property relies upon a priori knowledge of the position of the searched signals, which is usually not available. Recently, it has been shown that when applied in its standard form, MF may severely underestimate the PFA. As a consequence the statistical significance of features that belong to noise is overestimated and the resulting detections are actually spurious. For this reason, an alternative method of computing the PFA has been proposed that is based on the probability density function (PDF) of the peaks of an isotropic Gaussian random field. In this paper we further develop this method. In particular, we discuss the statistical meaning of the PFA and show that, although useful as a preliminary step in a detection procedure, it is not able to quantify the actual reliability of a specific detection. For this reason, a new quantity is introduced called the specific probability of false alarm (SPFA), which is able to carry out this computation. We show how this method works in targeted simulations and apply it to a few interferometric maps taken with the Atacama Large Millimeter/submillimeter Array (ALMA) and the Australia Telescope Compact Array (ATCA). We select a few potential new point sources and assign an accurate detection reliability to these sources.

  1. Variability of non-response to aspirin in patients with peripheral arterial occlusive disease during long-term follow-up.

    PubMed

    Linnemann, Birgit; Prochnow, Stephanie; Mani, Helen; Schwonberg, Jan; Lindhoff-Last, Edelgard

    2009-10-01

    Non-responsiveness to aspirin as detected by laboratory tests may identify patients at high risk for future vascular events. The aim of this prospective study was to evaluate whether non-responsiveness to aspirin is stable over time. Ninety-eight patients with stable peripheral arterial occlusive disease (PAOD) treated with 100 mg/d aspirin were followed over a median timeframe of 17 months. Platelet function tests were performed initially and at follow-up using arachidonic acid-induced light transmittance aggregometry (LTA) in native platelet-rich plasma with the Behring Coagulation Timer and by measuring the collagen-epinephrine closure time (CT) on a Platelet Function Analyzer (PFA-100). When determining platelet function using LTA, four patients (4.1%) had residual platelet function (i.e., MaxAggr > or =78%) despite aspirin treatment, whereas, according to the PFA-100 results, 12 patients (12.2%) were identified as non-responders (i.e., CT <192 s). Fifty-seven patients who were still under treatment with 100 mg/d aspirin at the time of follow-up provided a second blood sample. Further platelet function tests with the PFA-100 system identified a persistent non-responsiveness to aspirin over time in three patients (5.3%) whereas four (7.0%) and 15 (26.3%) patients had changes in response status when platelet function was assessed by LTA and on the PFA-100(R), respectively. We conclude that true non-responsiveness to aspirin is a rare phenomenon in stable PAOD patients. Furthermore, we conclude that in a number of patients, aspirin non-responsiveness is not stable over time.

  2. Confirmatory factor analysis for two questionnaires of caregiving in eating disorders

    PubMed Central

    Hibbs, Rebecca; Rhind, Charlotte; Sallis, Hannah; Goddard, Elizabeth; Raenker, Simone; Ayton, Agnes; Bamford, Bryony; Arcelus, Jon; Boughton, Nicky; Connan, Frances; Goss, Ken; Lazlo, Bert; Morgan, John; Moore, Kim; Robertson, David; Schreiber-Kounine, Christa; Sharma, Sonu; Whitehead, Linette; Lacey, Hubert; Schmidt, Ulrike; Treasure, Janet

    2014-01-01

    Objective: Caring for someone diagnosed with an eating disorder (ED) is associated with a high level of burden and psychological distress which can inadvertently contribute to the maintenance of the illness. The Eating Disorders Symptom Impact Scale (EDSIS) and Accommodation and Enabling Scale for Eating Disorders (AESED) are self-report scales to assess elements of caregiving theorised to contribute to the maintenance of an ED. Further validation and confirmation of the factor structures for these scales are necessary for rigorous evaluation of complex interventions which target these modifiable elements of caregiving. Method: EDSIS and AESED data from 268 carers of people with anorexia nervosa (AN), recruited from consecutive admissions to 15 UK inpatient or day patient hospital units, were subjected to confirmatory factor analysis to test model fit by applying the existing factor structures: (a) four-factor structure for the EDSIS and (b) five-factor structure for the AESED. Results: Confirmatory factor analytic results support the existing four-factor and five-factor structures for the EDSIS and the AESED, respectively. Discussion: The present findings provide further validation of the EDSIS and the AESED as tools to assess modifiable elements of caregiving for someone with an ED. PMID:25750785

  3. Analysis on influencing factors of EV charging station planning based on AHP

    NASA Astrophysics Data System (ADS)

    Yan, F.; Ma, X. F.

    2016-08-01

    As a new means of transport, electric vehicle (EV) is of great significance to alleviate the energy crisis. EV charging station planning has a far-reaching significance for the development of EV industry. This paper analyzes the impact factors of EV charging station planning, and then uses the analytic hierarchy process (AHP) to carry on the further analysis to the influencing factors, finally it gets the weight of each influence factor, and provides the basis for the evaluation scheme of the planning of charging stations for EV.

  4. Cardiometabolic Risk Clustering in Spinal Cord Injury: Results of Exploratory Factor Analysis

    PubMed Central

    2013-01-01

    Background: Evidence suggests an elevated prevalence of cardiometabolic risks among persons with spinal cord injury (SCI); however, the unique clustering of risk factors in this population has not been fully explored. Objective: The purpose of this study was to describe unique clustering of cardiometabolic risk factors differentiated by level of injury. Methods: One hundred twenty-one subjects (mean 37 ± 12 years; range, 18–73) with chronic C5 to T12 motor complete SCI were studied. Assessments included medical histories, anthropometrics and blood pressure, and fasting serum lipids, glucose, insulin, and hemoglobin A1c (HbA1c). Results: The most common cardiometabolic risk factors were overweight/obesity, high levels of low-density lipoprotein (LDL-C), and low levels of high-density lipoprotein (HDL-C). Risk clustering was found in 76.9% of the population. Exploratory principal component factor analysis using varimax rotation revealed a 3–factor model in persons with paraplegia (65.4% variance) and a 4–factor solution in persons with tetraplegia (73.3% variance). The differences between groups were emphasized by the varied composition of the extracted factors: Lipid Profile A (total cholesterol [TC] and LDL-C), Body Mass-Hypertension Profile (body mass index [BMI], systolic blood pressure [SBP], and fasting insulin [FI]); Glycemic Profile (fasting glucose and HbA1c), and Lipid Profile B (TG and HDL-C). BMI and SBP formed a separate factor only in persons with tetraplegia. Conclusions: Although the majority of the population with SCI has risk clustering, the composition of the risk clusters may be dependent on level of injury, based on a factor analysis group comparison. This is clinically plausible and relevant as tetraplegics tend to be hypo- to normotensive and more sedentary, resulting in lower HDL-C and a greater propensity toward impaired carbohydrate metabolism. PMID:23960702

  5. Cardiometabolic risk clustering in spinal cord injury: results of exploratory factor analysis.

    PubMed

    Libin, Alexander; Tinsley, Emily A; Nash, Mark S; Mendez, Armando J; Burns, Patricia; Elrod, Matt; Hamm, Larry F; Groah, Suzanne L

    2013-01-01

    Evidence suggests an elevated prevalence of cardiometabolic risks among persons with spinal cord injury (SCI); however, the unique clustering of risk factors in this population has not been fully explored. The purpose of this study was to describe unique clustering of cardiometabolic risk factors differentiated by level of injury. One hundred twenty-one subjects (mean 37 ± 12 years; range, 18-73) with chronic C5 to T12 motor complete SCI were studied. Assessments included medical histories, anthropometrics and blood pressure, and fasting serum lipids, glucose, insulin, and hemoglobin A1c (HbA1c). The most common cardiometabolic risk factors were overweight/obesity, high levels of low-density lipoprotein (LDL-C), and low levels of high-density lipoprotein (HDL-C). Risk clustering was found in 76.9% of the population. Exploratory principal component factor analysis using varimax rotation revealed a 3-factor model in persons with paraplegia (65.4% variance) and a 4-factor solution in persons with tetraplegia (73.3% variance). The differences between groups were emphasized by the varied composition of the extracted factors: Lipid Profile A (total cholesterol [TC] and LDL-C), Body Mass-Hypertension Profile (body mass index [BMI], systolic blood pressure [SBP], and fasting insulin [FI]); Glycemic Profile (fasting glucose and HbA1c), and Lipid Profile B (TG and HDL-C). BMI and SBP formed a separate factor only in persons with tetraplegia. Although the majority of the population with SCI has risk clustering, the composition of the risk clusters may be dependent on level of injury, based on a factor analysis group comparison. This is clinically plausible and relevant as tetraplegics tend to be hypo- to normotensive and more sedentary, resulting in lower HDL-C and a greater propensity toward impaired carbohydrate metabolism.

  6. A feasibility study on age-related factors of wrist pulse using principal component analysis.

    PubMed

    Jang-Han Bae; Young Ju Jeon; Sanghun Lee; Jaeuk U Kim

    2016-08-01

    Various analysis methods for examining wrist pulse characteristics are needed for accurate pulse diagnosis. In this feasibility study, principal component analysis (PCA) was performed to observe age-related factors of wrist pulse from various analysis parameters. Forty subjects in the age group of 20s and 40s were participated, and their wrist pulse signal and respiration signal were acquired with the pulse tonometric device. After pre-processing of the signals, twenty analysis parameters which have been regarded as values reflecting pulse characteristics were calculated and PCA was performed. As a results, we could reduce complex parameters to lower dimension and age-related factors of wrist pulse were observed by combining-new analysis parameter derived from PCA. These results demonstrate that PCA can be useful tool for analyzing wrist pulse signal.

  7. A Study of Item Bias for Attitudinal Measurement Using Maximum Likelihood Factor Analysis.

    ERIC Educational Resources Information Center

    Mayberry, Paul W.

    A technique for detecting item bias that is responsive to attitudinal measurement considerations is a maximum likelihood factor analysis procedure comparing multivariate factor structures across various subpopulations, often referred to as SIFASP. The SIFASP technique allows for factorial model comparisons in the testing of various hypotheses…

  8. A Comparison of Imputation Methods for Bayesian Factor Analysis Models

    ERIC Educational Resources Information Center

    Merkle, Edgar C.

    2011-01-01

    Imputation methods are popular for the handling of missing data in psychology. The methods generally consist of predicting missing data based on observed data, yielding a complete data set that is amiable to standard statistical analyses. In the context of Bayesian factor analysis, this article compares imputation under an unrestricted…

  9. Confirmatory Factor Analysis of the KABC-II in Preschool Children

    ERIC Educational Resources Information Center

    Morgan, Kimberly E.; Rothlisberg, Barbara A.; McIntosh, David E.; Hunt, Madeline S.

    2009-01-01

    The present study assessed the Kaufman Assessment Battery for Children, Second Edition (KABC-II) in relation to the synthesized Cattell-Horn-Carroll (CHC) theory of intelligence with a preschool sample. Participants were 200 preschool children between four and five years of age. A confirmatory factor analysis (CFA) was conducted, and different…

  10. Analysis of risk factors for central venous port failure in cancer patients

    PubMed Central

    Hsieh, Ching-Chuan; Weng, Hsu-Huei; Huang, Wen-Shih; Wang, Wen-Ke; Kao, Chiung-Lun; Lu, Ming-Shian; Wang, Chia-Siu

    2009-01-01

    AIM: To analyze the risk factors for central port failure in cancer patients administered chemotherapy, using univariate and multivariate analyses. METHODS: A total of 1348 totally implantable venous access devices (TIVADs) were implanted into 1280 cancer patients in this cohort study. A Cox proportional hazard model was applied to analyze risk factors for failure of TIVADs. Log-rank test was used to compare actuarial survival rates. Infection, thrombosis, and surgical complication rates (χ2 test or Fisher’s exact test) were compared in relation to the risk factors. RESULTS: Increasing age, male gender and open-ended catheter use were significant risk factors reducing survival of TIVADs as determined by univariate and multivariate analyses. Hematogenous malignancy decreased the survival time of TIVADs; this reduction was not statistically significant by univariate analysis [hazard ratio (HR) = 1.336, 95% CI: 0.966-1.849, P = 0.080)]. However, it became a significant risk factor by multivariate analysis (HR = 1.499, 95% CI: 1.079-2.083, P = 0.016) when correlated with variables of age, sex and catheter type. Close-ended (Groshong) catheters had a lower thrombosis rate than open-ended catheters (2.5% vs 5%, P = 0.015). Hematogenous malignancy had higher infection rates than solid malignancy (10.5% vs 2.5%, P < 0.001). CONCLUSION: Increasing age, male gender, open-ended catheters and hematogenous malignancy were risk factors for TIVAD failure. Close-ended catheters had lower thrombosis rates and hematogenous malignancy had higher infection rates. PMID:19787834

  11. Risk factors for incidental durotomy during lumbar surgery: a retrospective study by multivariate analysis.

    PubMed

    Chen, Zhixiang; Shao, Peng; Sun, Qizhao; Zhao, Dong

    2015-03-01

    The purpose of the present study was to use a prospectively collected data to evaluate the rate of incidental durotomy (ID) during lumbar surgery and determine the associated risk factors by using univariate and multivariate analysis. We retrospectively reviewed 2184 patients who underwent lumbar surgery from January 1, 2009 to December 31, 2011 at a single hospital. Patients with ID (n=97) were compared with the patients without ID (n=2019). The influences of several potential risk factors that might affect the occurrence of ID were assessed using univariate and multivariate analyses. The overall incidence of ID was 4.62%. Univariate analysis demonstrated that older age, diabetes, lumbar central stenosis, posterior approach, revision surgery, prior lumber surgery and minimal invasive surgery are risk factors for ID during lumbar surgery. However, multivariate analysis identified older age, prior lumber surgery, revision surgery, and minimally invasive surgery as independent risk factors. Older age, prior lumber surgery, revision surgery, and minimal invasive surgery were independent risk factors for ID during lumbar surgery. These findings may guide clinicians making future surgical decisions regarding ID and aid in the patient counseling process to alleviate risks and complications. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Method for exploiting bias in factor analysis using constrained alternating least squares algorithms

    DOEpatents

    Keenan, Michael R.

    2008-12-30

    Bias plays an important role in factor analysis and is often implicitly made use of, for example, to constrain solutions to factors that conform to physical reality. However, when components are collinear, a large range of solutions may exist that satisfy the basic constraints and fit the data equally well. In such cases, the introduction of mathematical bias through the application of constraints may select solutions that are less than optimal. The biased alternating least squares algorithm of the present invention can offset mathematical bias introduced by constraints in the standard alternating least squares analysis to achieve factor solutions that are most consistent with physical reality. In addition, these methods can be used to explicitly exploit bias to provide alternative views and provide additional insights into spectral data sets.

  13. Rotation Criteria and Hypothesis Testing for Exploratory Factor Analysis: Implications for Factor Pattern Loadings and Interfactor Correlations

    ERIC Educational Resources Information Center

    Schmitt, Thomas A.; Sass, Daniel A.

    2011-01-01

    Exploratory factor analysis (EFA) has long been used in the social sciences to depict the relationships between variables/items and latent traits. Researchers face many choices when using EFA, including the choice of rotation criterion, which can be difficult given that few research articles have discussed and/or demonstrated their differences.…

  14. The combined use of dynamic factor analysis and wavelet analysis to evaluate latent factors controlling complex groundwater level fluctuations in a riverside alluvial aquifer

    NASA Astrophysics Data System (ADS)

    Oh, Yun-Yeong; Yun, Seong-Taek; Yu, Soonyoung; Hamm, Se-Yeong

    2017-12-01

    To identify and quantitatively evaluate complex latent factors controlling groundwater level (GWL) fluctuations in a riverside alluvial aquifer influenced by barrage construction, we developed the combined use of dynamic factor analysis (DFA) and wavelet analysis (WA). Time series data of GWL, river water level and precipitation were collected for 3 years (July 2012 to June 2015) from an alluvial aquifer underneath an agricultural area of the Nakdong river basin, South Korea. Based on the wavelet coefficients of the final approximation, the GWL data was clustered into three groups (WCG1 to WCG3). Two dynamic factors (DFs) were then extracted using DFA for each group; thus, six major factors were extracted. Next, the time-frequency variability of the extracted DFs was examined using multiresolution cross-correlation analysis (MRCCA) with the following steps: 1) major driving forces and their scales in GWL fluctuations were identified by comparing maximum correlation coefficients (rmax) between DFs and the GWL time series and 2) the results were supplemented using the wavelet transformed coherence (WTC) analysis between DFs and the hydrological time series. Finally, relative contributions of six major DFs to the GWL fluctuations could be quantitatively assessed by calculating the effective dynamic efficiency (Def). The characteristics and relevant process of the identified six DFs are: 1) WCG1DF4,1 as an indicative of seasonal agricultural pumping (scales = 64-128 days; rmax = 0.68-0.89; Def ≤ 23.1%); 2) WCG1DF4,4 representing the cycle of regional groundwater recharge (scales = 64-128 days; rmax = 0.98-1.00; Def ≤ 11.1%); 3) WCG2DF4,1 indicating the complex interaction between the episodes of precipitation and direct runoff (scales = 2-8 days; rmax = 0.82-0.91; Def ≤ 35.3%) and seasonal GW-RW interaction (scales = 64-128 days; rmax = 0.76-0.91; Def ≤ 14.2%); 4) WCG2DF4,4 reflecting the complex effects of seasonal pervasive pumping and the local recharge

  15. Human Modeling for Ground Processing Human Factors Engineering Analysis

    NASA Technical Reports Server (NTRS)

    Stambolian, Damon B.; Lawrence, Brad A.; Stelges, Katrine S.; Steady, Marie-Jeanne O.; Ridgwell, Lora C.; Mills, Robert E.; Henderson, Gena; Tran, Donald; Barth, Tim

    2011-01-01

    There have been many advancements and accomplishments over the last few years using human modeling for human factors engineering analysis for design of spacecraft. The key methods used for this are motion capture and computer generated human models. The focus of this paper is to explain the human modeling currently used at Kennedy Space Center (KSC), and to explain the future plans for human modeling for future spacecraft designs

  16. Psychometric evaluation of the revised Illness Perception Questionnaire (IPQ-R) in cancer patients: confirmatory factor analysis and Rasch analysis.

    PubMed

    Ashley, Laura; Smith, Adam B; Keding, Ada; Jones, Helen; Velikova, Galina; Wright, Penny

    2013-12-01

    To provide new insights into the psychometrics of the revised Illness Perception Questionnaire (IPQ-R) in cancer patients. To undertake, for the first time using data from breast, colorectal and prostate cancer patients, a confirmatory factor analysis (CFA) to assess the validity of the IPQ-R's core seven-factor structure. Also, for the first time in any illness group, to undertake Rasch analysis to explore the extent to which the IPQ-R factors form unidimensional scales, with linear measurement properties and no Differential Item Functioning (DIF). Patients with potentially curable breast, colorectal or prostate cancer, within 6months post-diagnosis, completed the IPQ-R online (N=531). CFA was conducted, including multi-sample analysis, and for each IPQ-R factor fit to the Rasch model was assessed by examining, amongst other things, item fit, DIF and unidimensionality. The CFA showed a moderate fit of the data to the IPQ-R model, and stability across diagnosis, although fit was significantly improved following the removal of selected items. All seven factors achieved fit to the Rasch model, and exhibited unidimensionality and minimal DIF, although in most cases this was after some item rescoring and/or deletion. In both analyses, IPQ-R items 12, 18 and 24 were indicated as misfitting and removed. Given the rigorous standard of Rasch measurement, and the generic nature of the IPQ-R, it stood up well to the demands of the Rasch model in this study. Importantly, the results show that with some relatively minor, pragmatic modifications the IPQ-R could possess Rasch-standard measurement in cancer patients. © 2013.

  17. Human error and commercial aviation accidents: an analysis using the human factors analysis and classification system.

    PubMed

    Shappell, Scott; Detwiler, Cristy; Holcomb, Kali; Hackworth, Carla; Boquet, Albert; Wiegmann, Douglas A

    2007-04-01

    The aim of this study was to extend previous examinations of aviation accidents to include specific aircrew, environmental, supervisory, and organizational factors associated with two types of commercial aviation (air carrier and commuter/ on-demand) accidents using the Human Factors Analysis and Classification System (HFACS). HFACS is a theoretically based tool for investigating and analyzing human error associated with accidents and incidents. Previous research has shown that HFACS can be reliably used to identify human factors trends associated with military and general aviation accidents. Using data obtained from both the National Transportation Safety Board and the Federal Aviation Administration, 6 pilot-raters classified aircrew, supervisory, organizational, and environmental causal factors associated with 1020 commercial aviation accidents that occurred over a 13-year period. The majority of accident causal factors were attributed to aircrew and the environment, with decidedly fewer associated with supervisory and organizational causes. Comparisons were made between HFACS causal categories and traditional situational variables such as visual conditions, injury severity, and regional differences. These data will provide support for the continuation, modification, and/or development of interventions aimed at commercial aviation safety. HFACS provides a tool for assessing human factors associated with accidents and incidents.

  18. Factor analysis of the Mayo-Portland Adaptability Inventory: structure and validity.

    PubMed

    Bohac, D L; Malec, J F; Moessner, A M

    1997-07-01

    Principal-components (PC) factor analysis of the Mayo-Portland Adaptability Inventory (MPAI) was conducted using a sample of outpatients (n = 189) with acquired brain injury (ABI) to evaluate whether outcome after ABI is multifactorial or unifactorial in nature. An eight-factor model was derived which explained 64-4% of the total variance. The eight factors were interpreted as representing Activities of Daily Living, Social Initiation, Cognition, Impaired-Self-awareness/Distress, Social Skills/ Support, Independence, Visuoperceptual, and Psychiatric, respectively. Validation of the Cognition factor was supported when factor scores were correlated with various neuropsychological measures. In addition, 117 patient self-rating total scores were used to evaluate the Impaired Self-awareness/Distress factor. An inverse relationship was observed, supporting this factor's ability to capture the two-dimensional phenomena of diminished self-awareness or enhanced emotional distress. A new subscale structure is suggested, that may allow greater clinical utility in understanding how ABI manifests in patients, and may provide clinicians with a better structure for implementing treatment strategies to address specific areas of impairment and disability for specific patients. Additionally, more precise measurement of treatment outcomes may be afforded by this reorganization.

  19. Analysis of psychological factors for quality assessment of interactive multimodal service

    NASA Astrophysics Data System (ADS)

    Yamagishi, Kazuhisa; Hayashi, Takanori

    2005-03-01

    We proposed a subjective quality assessment model for interactive multimodal services. First, psychological factors of an audiovisual communication service were extracted by using the semantic differential (SD) technique and factor analysis. Forty subjects participated in subjective tests and performed point-to-point conversational tasks on a PC-based TV phone that exhibits various network qualities. The subjects assessed those qualities on the basis of 25 pairs of adjectives. Two psychological factors, i.e., an aesthetic feeling and a feeling of activity, were extracted from the results. Then, quality impairment factors affecting these two psychological factors were analyzed. We found that the aesthetic feeling is mainly affected by IP packet loss and video coding bit rate, and the feeling of activity depends on delay time and video frame rate. We then proposed an opinion model derived from the relationships among quality impairment factors, psychological factors, and overall quality. The results indicated that the estimation error of the proposed model is almost equivalent to the statistical reliability of the subjective score. Finally, using the proposed model, we discuss guidelines for quality design of interactive audiovisual communication services.

  20. Simulating the Effects of Common and Specific Abilities on Test Performance: An Evaluation of Factor Analysis

    ERIC Educational Resources Information Center

    McFarland, Dennis J.

    2014-01-01

    Purpose: Factor analysis is a useful technique to aid in organizing multivariate data characterizing speech, language, and auditory abilities. However, knowledge of the limitations of factor analysis is essential for proper interpretation of results. The present study used simulated test scores to illustrate some characteristics of factor…

  1. Confirmatory Factor Analysis of the Bases of Leader Power: First-Order Factor Model and Its Invariance Across Groups.

    PubMed

    Rahim, M A; Magner, N R

    1996-10-01

    Confirmatory factor analyses of data (from five samples: N = 308 accountants and finance professionals, N = 578 management and non-management employees, and N = 588 employed management students in the U.S.; N = 728 management and non-management employees in S. Korea, N = 250 management and non-management bank employees in Bangladesh) on the 29 items of the Rahim Leader Power Inventory were performed with LISREL 7. The results provided support for the convergent and discriminant validities of the subscales measuring the five bases of leader power (coercive, reward, legitimate, expert, and referent), and the invariance of factor pattern and factor loadings across organizational levels and the three American samples. Additional analysis indicated that leader power profiles differed across the three national cultures represented in the study.

  2. Replace-approximation method for ambiguous solutions in factor analysis of ultrasonic hepatic perfusion

    NASA Astrophysics Data System (ADS)

    Zhang, Ji; Ding, Mingyue; Yuchi, Ming; Hou, Wenguang; Ye, Huashan; Qiu, Wu

    2010-03-01

    Factor analysis is an efficient technique to the analysis of dynamic structures in medical image sequences and recently has been used in contrast-enhanced ultrasound (CEUS) of hepatic perfusion. Time-intensity curves (TICs) extracted by factor analysis can provide much more diagnostic information for radiologists and improve the diagnostic rate of focal liver lesions (FLLs). However, one of the major drawbacks of factor analysis of dynamic structures (FADS) is nonuniqueness of the result when only the non-negativity criterion is used. In this paper, we propose a new method of replace-approximation based on apex-seeking for ambiguous FADS solutions. Due to a partial overlap of different structures, factor curves are assumed to be approximately replaced by the curves existing in medical image sequences. Therefore, how to find optimal curves is the key point of the technique. No matter how many structures are assumed, our method always starts to seek apexes from one-dimensional space where the original high-dimensional data is mapped. By finding two stable apexes from one dimensional space, the method can ascertain the third one. The process can be continued until all structures are found. This technique were tested on two phantoms of blood perfusion and compared to the two variants of apex-seeking method. The results showed that the technique outperformed two variants in comparison of region of interest measurements from phantom data. It can be applied to the estimation of TICs derived from CEUS images and separation of different physiological regions in hepatic perfusion.

  3. Analysis of factors that influencing the interest of Bali State Polytechnic’s students in entrepreneurship

    NASA Astrophysics Data System (ADS)

    Ayuni, N. W. D.; Sari, I. G. A. M. K. K.

    2018-01-01

    The high rate of unemployment results the economic growth to be hampered. To solve this situation, the government try to change the students’ mindset from becoming a job seeker to become a job creator or entrepreneur. One real action that usually been held in Bali State Polytechnic is Student Entrepreneurial Program. The purpose of this research is to identify and analyze the factors that influence the interest of Bali State Polytechnic’s Students in entrepreneurship, especially in the Entrepreneurial Student Program. Method used in this research is Factor Analysis including Bartlett Test, Kaiser-Mayer Olkin (KMO), Measure of Sampling Adequacy (MSA), factor extraction using Principal Component Analysis (PCA), factor selection using eigen value and scree plot, and factor rotation using orthogonal rotation varimax. Result shows that there are four factors that influencing the interest of Bali State Polytechnic’s Students in Entrepreneurship which are Contextual Factor (including Entrepreneurship Training, Academic Support, Perceived Confidence, and Economic Challenge), Self Efficacy Factor (including Leadership, Mental Maturity, Relation with Entrepreneur, and Authority), Subjective Norm Factor (including Support of Important Relative, Support of Friends, and Family Role), and Attitude Factor (including Self Realization).

  4. Patient Safety Culture Survey in Pediatric Complex Care Settings: A Factor Analysis.

    PubMed

    Hessels, Amanda J; Murray, Meghan; Cohen, Bevin; Larson, Elaine L

    2017-04-19

    Children with complex medical needs are increasing in number and demanding the services of pediatric long-term care facilities (pLTC), which require a focus on patient safety culture (PSC). However, no tool to measure PSC has been tested in this unique hybrid acute care-residential setting. The objective of this study was to evaluate the psychometric properties of the Nursing Home Survey on Patient Safety Culture tool slightly modified for use in the pLTC setting. Factor analyses were performed on data collected from 239 staff at 3 pLTC in 2012. Items were screened by principal axis factoring, and the original structure was tested using confirmatory factor analysis. Exploratory factor analysis was conducted to identify the best model fit for the pLTC data, and factor reliability was assessed by Cronbach alpha. The extracted, rotated factor solution suggested items in 4 (staffing, nonpunitive response to mistakes, communication openness, and organizational learning) of the original 12 dimensions may not be a good fit for this population. Nevertheless, in the pLTC setting, both the original and the modified factor solutions demonstrated similar reliabilities to the published consistencies of the survey when tested in adult nursing homes and the items factored nearly identically as theorized. This study demonstrates that the Nursing Home Survey on Patient Safety Culture with minimal modification may be an appropriate instrument to measure PSC in pLTC settings. Additional psychometric testing is recommended to further validate the use of this instrument in this setting, including examining the relationship to safety outcomes. Increased use will yield data for benchmarking purposes across these specialized settings to inform frontline workers and organizational leaders of areas of strength and opportunity for improvement.

  5. A Bayes factor meta-analysis of Bem's ESP claim.

    PubMed

    Rouder, Jeffrey N; Morey, Richard D

    2011-08-01

    In recent years, statisticians and psychologists have provided the critique that p-values do not capture the evidence afforded by data and are, consequently, ill suited for analysis in scientific endeavors. The issue is particular salient in the assessment of the recent evidence provided for ESP by Bem (2011) in the mainstream Journal of Personality and Social Psychology. Wagenmakers, Wetzels, Borsboom, and van der Maas (Journal of Personality and Social Psychology, 100, 426-432, 2011) have provided an alternative Bayes factor assessment of Bem's data, but their assessment was limited to examining each experiment in isolation. We show here that the variant of the Bayes factor employed by Wagenmakers et al. is inappropriate for making assessments across multiple experiments, and cannot be used to gain an accurate assessment of the total evidence in Bem's data. We develop a meta-analytic Bayes factor that describes how researchers should update their prior beliefs about the odds of hypotheses in light of data across several experiments. We find that the evidence that people can feel the future with neutral and erotic stimuli to be slight, with Bayes factors of 3.23 and 1.57, respectively. There is some evidence, however, for the hypothesis that people can feel the future with emotionally valenced nonerotic stimuli, with a Bayes factor of about 40. Although this value is certainly noteworthy, we believe it is orders of magnitude lower than what is required to overcome appropriate skepticism of ESP.

  6. Molecular genetic analysis of activation-tagged transcription factors thought to be involved in photomorphogenesis

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

    Neff, Michael M.

    This is a final report for Department of Energy Grant No. DE-FG02-08ER15927 entitled “Molecular Genetic Analysis of Activation-Tagged Transcription Factors Thought to be Involved in Photomorphogenesis”. Based on our preliminary photobiological and genetic analysis of the sob1-D mutant, we hypothesized that OBP3 is a transcription factor involved in both phytochrome and cryptochrome-mediated signal transduction. In addition, we hypothesized that OBP3 is involved in auxin signaling and root development. Based on our preliminary photobiological and genetic analysis of the sob2-D mutant, we also hypothesized that a related gene, LEP, is involved in hormone signaling and seedling development.

  7. Risk Factors for Suicide Ideation Among Adolescents: Five-Year National Data Analysis.

    PubMed

    Im, Yeojin; Oh, Won-Oak; Suk, Minhyun

    2017-06-01

    This study identified risk factors for suicide ideation among adolescents through a secondary analysis using data collected over five years from the 5th-9th Korea Youth Risk Behavior Survey. We analyzed 370,568 students' responses to questions about suicidality. The risk factors for suicide ideation included demographic characteristics, such as gender (girls), low grades, low economic status, and not living with one or both parents. Behavioral and mental health risk factors affecting suicide ideation were depression, low sleep satisfaction, high stress, alcohol consumption, smoking, and sexual activity. Health care providers should particularly target adolescents manifesting the above risk factors when developing suicide prevention programs for them. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Hybrid PV/diesel solar power system design using multi-level factor analysis optimization

    NASA Astrophysics Data System (ADS)

    Drake, Joshua P.

    Solar power systems represent a large area of interest across a spectrum of organizations at a global level. It was determined that a clear understanding of current state of the art software and design methods, as well as optimization methods, could be used to improve the design methodology. Solar power design literature was researched for an in depth understanding of solar power system design methods and algorithms. Multiple software packages for the design and optimization of solar power systems were analyzed for a critical understanding of their design workflow. In addition, several methods of optimization were studied, including brute force, Pareto analysis, Monte Carlo, linear and nonlinear programming, and multi-way factor analysis. Factor analysis was selected as the most efficient optimization method for engineering design as it applied to solar power system design. The solar power design algorithms, software work flow analysis, and factor analysis optimization were combined to develop a solar power system design optimization software package called FireDrake. This software was used for the design of multiple solar power systems in conjunction with an energy audit case study performed in seven Tibetan refugee camps located in Mainpat, India. A report of solar system designs for the camps, as well as a proposed schedule for future installations was generated. It was determined that there were several improvements that could be made to the state of the art in modern solar power system design, though the complexity of current applications is significant.

  9. Human Factors Operability Timeline Analysis to Improve the Processing Flow of the Orion Spacecraft

    NASA Technical Reports Server (NTRS)

    Stambolian, Damon B.; Schlierf, Roland; Miller, Darcy; Posada, Juan; Haddock, Mike; Haddad, Mike; Tran, Donald; Henderon, Gena; Barth, Tim

    2011-01-01

    This slide presentation reviews the use of Human factors and timeline analysis to have a more efficient and effective processing flow. The solution involved developing a written timeline of events that included each activity within each functional flow block. Each activity had computer animation videos and pictures of the people involved and the hardware. The Human Factors Engineering Analysis Tool (HFEAT) was improved by modifying it to include the timeline of events. The HFEAT was used to define the human factors requirements and design solutions were developed for these requirements. An example of a functional flow block diagram is shown, and a view from one of the animations (i.e., short stack pallet) is shown and explained.

  10. Coping Patterns of African American Adolescents: A Confirmatory Factor Analysis and Cluster Analysis of the Children's Coping Strategies Checklist

    ERIC Educational Resources Information Center

    Gaylord-Harden, Noni K.; Gipson, Polly; Mance, GiShawn; Grant, Kathryn E.

    2008-01-01

    The current study examined patterns of coping strategies in a sample of 497 low-income urban African American adolescents (mean age = 12.61 years). Results of confirmatory factor analysis indicated that the 4-factor structure of the Children's Coping Strategies Checklist (T. S. Ayers, I. N. Sandler, S. G. West, & M. W. Roosa, 1996) was not…

  11. [Analysis of characteristics and influence factors of diagnostic delay of endometriosis].

    PubMed

    Han, X T; Guo, H Y; Kong, D L; Han, J S; Zhang, L F

    2018-02-25

    Objective: To access the influence factors of diagnostic delay of endometriosis. Methods: We designed a questionnaire of diagnostic delay of endometriosis. From February 2014 to February 2016, 400 patients who had dysmenorrhea and diagnosed with endometriosis by surgery in Peking University Third Hospital were surveyed retrospectively. Time and risk factors of diagnostic delay were analyzed. Results: The diagnostic delay of 400 patients was 13.0 years (0.2-43.0 years), 78.5%(314/400) patients thought pain was a normal phenomenon and didn't see the doctor. Patients who suffered dysmenorrhea at menarche experienced longer diagnostic delay than those who had dysmenorrhea after menarche (18.0 vs 4.5 years; Z= 191.800, P< 0.01) . Patients who suffered aggravating dysmenorrhea experienced shorter delay time than those who suffered stable or relieving dysmenorrhea (11.0 vs 12.5 vs 18.0 years; Z= 8.270, P< 0.05) , with the difference statistically significant, single factor analysis shows. Severe dysmenorrhea, deep infiltration endometriosis (DIE) , family history of dysmenorrhea or endometriosis, previous surgical history of endometriosis, high stage, with infertility, adenomyoma or other symptoms, could help to shorten diagnostic delay with no significant difference ( P> 0.05) . By multiple logistic regression analysis, the results shown that whether have dysmenorrhea at menarche and clinical diagnosis time were the independent factors affecting delayed diagnosis ( P< 0.01) . Conclusions: Diagnostic delay of endometriosis is common and the mean delay time is 13.0 years mainly due to the unawareness of dysmenorrhea. Dysmenorrhea at menarche, clinical diagnosis time and dysmenorrhea intensity are the factors affecting time of diagnostic delay.

  12. A projection operator method for the analysis of magnetic neutron form factors

    NASA Astrophysics Data System (ADS)

    Kaprzyk, S.; Van Laar, B.; Maniawski, F.

    1981-03-01

    A set of projection operators in matrix form has been derived on the basis of decomposition of the spin density into a series of fully symmetrized cubic harmonics. This set of projection operators allows a formulation of the Fourier analysis of magnetic form factors in a convenient way. The presented method is capable of checking the validity of various theoretical models used for spin density analysis up to now. The general formalism is worked out in explicit form for the fcc and bcc structures and deals with that part of spin density which is contained within the sphere inscribed in the Wigner-Seitz cell. This projection operator method has been tested on the magnetic form factors of nickel and iron.

  13. Factor Analysis of the Alcohol and Drug Confrontation Scale (ADCS)

    PubMed Central

    Polcin, Douglas L.; Galloway, Gantt P.; Bostrom, Alan; Greenfield, Thomas K.

    2007-01-01

    The Alcohol and Drug Confrontation Scale (ADCS) is a 72-item instrument that defines confrontation as an individual being told “bad things” might happen if they do not make changes to address alcohol or drug problems or maintain sobriety. Preliminary assessment of the ADCS using substance abusers entering SLH's revealed: 1) Scale items were frequently endorsed; 2) Confrontation was often experienced as accurate and helpful; and 3) Confronters' statements were viewed supportive and accurate. This study reports the results of a factor analysis on a larger sample 179 participants using baseline and 6 month follow-up data. Results yielded a clear two factor solution: 1) Internal Support (alpha = 0.80) and 2) External Intensity (alpha = 0.63). The two factors accounted for 58% of the variance. The ADCS offers a fresh and broader view of confrontation that can be reliably measured. PMID:17270360

  14. Women with Red Hair Report A Slightly Increased Rate of Bruising, but Have Normal Coagulation Tests

    PubMed Central

    Liem, Edwin B.; Hollensead, Sandra C.; Joiner, Teresa V.

    2005-01-01

    There is an anecdotal impression that redheads experience more perioperative bleeding complications than those with other hair colors. We, therefore, tested the hypothesis that perceived problems with hemostasis could be detected with commonly used coagulation tests. Se studied healthy female Caucasian volunteers, 18 to 40 years, comparable in terms of height, weight, and age, with natural bright red (n = 25) or black or dark brown (n = 26) hair. Volunteers were questioned about their bleeding history and the following tests were performed: complete blood count, prothrombin time/international normalized ratio, activated partial thromboplastin time, platelet function analysis (PFA-100), and platelet aggregation using standard turbidimetric methodology. Agonists for aggregation were adenosine diphosphate, arachidonic acid, collagen, epinephrine, and two concentrations of ristocetin. The red-haired volunteers reported significantly more bruising, but there were no significant differences between the red- and dark-haired groups in hemoglobin concentration, platelet numbers, prothrombin time/international normalized ratio, or activated partial thromboplastin time. Furthermore, no significant differences in platelet function, as measured with the PFA-100 or with platelet aggregometry, were observed. We conclude that if redheads have hemostasis abnormalities, they are subtle. PMID:16368849

  15. Using decision tree analysis to identify risk factors for relapse to smoking

    PubMed Central

    Piper, Megan E.; Loh, Wei-Yin; Smith, Stevens S.; Japuntich, Sandra J.; Baker, Timothy B.

    2010-01-01

    This research used classification tree analysis and logistic regression models to identify risk factors related to short- and long-term abstinence. Baseline and cessation outcome data from two smoking cessation trials, conducted from 2001 to 2002, in two Midwestern urban areas, were analyzed. There were 928 participants (53.1% women, 81.8% white) with complete data. Both analyses suggest that relapse risk is produced by interactions of risk factors and that early and late cessation outcomes reflect different vulnerability factors. The results illustrate the dynamic nature of relapse risk and suggest the importance of efficient modeling of interactions in relapse prediction. PMID:20397871

  16. The Potential Benefits of Applying Recent Advances in Esophageal Motility Testing in Patients with Esophageal Atresia

    PubMed Central

    Rommel, Nathalie; Rayyan, Maissa; Scheerens, Charlotte; Omari, Taher

    2017-01-01

    Infants and children with esophageal atresia commonly present with swallowing dysfunction or dysphagia. Dysphagia can lead to a range of significant consequences such as aspiration pneumonia, malnutrition, dehydration, and food impaction. To improve oral intake, the clinical diagnosis of dysphagia in patients with esophageal atresia should focus on both the pharynx and the esophagus. To characterize the complex interactions of bolus flow and motor function between mouth, pharynx, and esophagus, a detailed understanding of normal and abnormal deglutition is required through the use of adequate and objective assessment techniques. As clinical symptoms do not correlate well with conventional assessment methods of motor function such as radiology or manometry but do correlate with bolus flow, the current state-of-the-art diagnosis involves high-resolution manometry combined with impedance measurements to characterize the interplay between esophageal motor function and bolus clearance. Using a novel pressure flow analysis (PFA) method as an integrated analysis method of manometric and impedance measurements, differentiation of patients with impaired esophago-gastric junction relaxation from patients with bolus outflow disorders is clinically relevant. In this, pressure flow matrix categorizing the quantitative PFA measures may be used to make rational therapeutic decisions in patients with esophageal atresia. Through more advanced diagnostics, improved understanding of pathophysiology may improve our patient care by directly targeting the failed biomechanics of both the pharynx and the esophagus. PMID:28680874

  17. The Potential Benefits of Applying Recent Advances in Esophageal Motility Testing in Patients with Esophageal Atresia.

    PubMed

    Rommel, Nathalie; Rayyan, Maissa; Scheerens, Charlotte; Omari, Taher

    2017-01-01

    Infants and children with esophageal atresia commonly present with swallowing dysfunction or dysphagia. Dysphagia can lead to a range of significant consequences such as aspiration pneumonia, malnutrition, dehydration, and food impaction. To improve oral intake, the clinical diagnosis of dysphagia in patients with esophageal atresia should focus on both the pharynx and the esophagus. To characterize the complex interactions of bolus flow and motor function between mouth, pharynx, and esophagus, a detailed understanding of normal and abnormal deglutition is required through the use of adequate and objective assessment techniques. As clinical symptoms do not correlate well with conventional assessment methods of motor function such as radiology or manometry but do correlate with bolus flow, the current state-of-the-art diagnosis involves high-resolution manometry combined with impedance measurements to characterize the interplay between esophageal motor function and bolus clearance. Using a novel pressure flow analysis (PFA) method as an integrated analysis method of manometric and impedance measurements, differentiation of patients with impaired esophago-gastric junction relaxation from patients with bolus outflow disorders is clinically relevant. In this, pressure flow matrix categorizing the quantitative PFA measures may be used to make rational therapeutic decisions in patients with esophageal atresia. Through more advanced diagnostics, improved understanding of pathophysiology may improve our patient care by directly targeting the failed biomechanics of both the pharynx and the esophagus.

  18. A retrospective analysis to identify the factors affecting infection in patients undergoing chemotherapy.

    PubMed

    Park, Ji Hyun; Kim, Hyeon-Young; Lee, Hanna; Yun, Eun Kyoung

    2015-12-01

    This study compares the performance of the logistic regression and decision tree analysis methods for assessing the risk factors for infection in cancer patients undergoing chemotherapy. The subjects were 732 cancer patients who were receiving chemotherapy at K university hospital in Seoul, Korea. The data were collected between March 2011 and February 2013 and were processed for descriptive analysis, logistic regression and decision tree analysis using the IBM SPSS Statistics 19 and Modeler 15.1 programs. The most common risk factors for infection in cancer patients receiving chemotherapy were identified as alkylating agents, vinca alkaloid and underlying diabetes mellitus. The logistic regression explained 66.7% of the variation in the data in terms of sensitivity and 88.9% in terms of specificity. The decision tree analysis accounted for 55.0% of the variation in the data in terms of sensitivity and 89.0% in terms of specificity. As for the overall classification accuracy, the logistic regression explained 88.0% and the decision tree analysis explained 87.2%. The logistic regression analysis showed a higher degree of sensitivity and classification accuracy. Therefore, logistic regression analysis is concluded to be the more effective and useful method for establishing an infection prediction model for patients undergoing chemotherapy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Determination of important topographic factors for landslide mapping analysis using MLP network.

    PubMed

    Alkhasawneh, Mutasem Sh; Ngah, Umi Kalthum; Tay, Lea Tien; Mat Isa, Nor Ashidi; Al-batah, Mohammad Subhi

    2013-01-01

    Landslide is one of the natural disasters that occur in Malaysia. Topographic factors such as elevation, slope angle, slope aspect, general curvature, plan curvature, and profile curvature are considered as the main causes of landslides. In order to determine the dominant topographic factors in landslide mapping analysis, a study was conducted and presented in this paper. There are three main stages involved in this study. The first stage is the extraction of extra topographic factors. Previous landslide studies had identified mainly six topographic factors. Seven new additional factors have been proposed in this study. They are longitude curvature, tangential curvature, cross section curvature, surface area, diagonal line length, surface roughness, and rugosity. The second stage is the specification of the weight of each factor using two methods. The methods are multilayer perceptron (MLP) network classification accuracy and Zhou's algorithm. At the third stage, the factors with higher weights were used to improve the MLP performance. Out of the thirteen factors, eight factors were considered as important factors, which are surface area, longitude curvature, diagonal length, slope angle, elevation, slope aspect, rugosity, and profile curvature. The classification accuracy of multilayer perceptron neural network has increased by 3% after the elimination of five less important factors.

  20. Determination of Important Topographic Factors for Landslide Mapping Analysis Using MLP Network

    PubMed Central

    Alkhasawneh, Mutasem Sh.; Ngah, Umi Kalthum; Mat Isa, Nor Ashidi; Al-batah, Mohammad Subhi

    2013-01-01

    Landslide is one of the natural disasters that occur in Malaysia. Topographic factors such as elevation, slope angle, slope aspect, general curvature, plan curvature, and profile curvature are considered as the main causes of landslides. In order to determine the dominant topographic factors in landslide mapping analysis, a study was conducted and presented in this paper. There are three main stages involved in this study. The first stage is the extraction of extra topographic factors. Previous landslide studies had identified mainly six topographic factors. Seven new additional factors have been proposed in this study. They are longitude curvature, tangential curvature, cross section curvature, surface area, diagonal line length, surface roughness, and rugosity. The second stage is the specification of the weight of each factor using two methods. The methods are multilayer perceptron (MLP) network classification accuracy and Zhou's algorithm. At the third stage, the factors with higher weights were used to improve the MLP performance. Out of the thirteen factors, eight factors were considered as important factors, which are surface area, longitude curvature, diagonal length, slope angle, elevation, slope aspect, rugosity, and profile curvature. The classification accuracy of multilayer perceptron neural network has increased by 3% after the elimination of five less important factors. PMID:24453846