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Effect Analysis (effect + analysis)
Selected AbstractsVariation Mode and Effect Analysis: a Practical Tool for Quality ImprovementQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 8 2006Per Johansson Abstract This paper describes a statistically based engineering method, variation mode and effect analysis (VMEA), that facilitates an understanding of variation and highlights the product/process areas in which improvement efforts should be targeted. An industrial application is also described to illustrate how the VMEA can be used for quality improvement purposes. Copyright © 2006 John Wiley & Sons, Ltd. [source] GENETIC STUDY: FULL ARTICLE: Incorporating age at onset of smoking into genetic models for nicotine dependence: evidence for interaction with multiple genesADDICTION BIOLOGY, Issue 3 2010Richard A. Grucza ABSTRACT Nicotine dependence is moderately heritable, but identified genetic associations explain only modest portions of this heritability. We analyzed 3369 SNPs from 349 candidate genes and investigated whether incorporation of SNP-by-environment interaction into association analyses might bolster gene discovery efforts and prediction of nicotine dependence. Specifically, we incorporated the interaction between allele count and age at onset of regular smoking (AOS) into association analyses of nicotine dependence. Subjects were from the Collaborative Genetic Study of Nicotine Dependence and included 797 cases ascertained for Fagerström nicotine dependence and 811 non-nicotine-dependent smokers as controls, all of European descent. Compared with main effect models, SNP × AOS interaction models resulted in higher numbers of nominally significant tests, increased predictive utility at individual SNPs and higher predictive utility in a multi-locus model. Some SNPs previously documented in main effect analyses exhibited improved fits in the joint analysis, including rs16969968 from CHRNA5 and rs2314379 from MAP3K4. CHRNA5 exhibited larger effects in later-onset smokers, in contrast with a previous report that suggested the opposite interaction (Weiss et al. 2008). However, a number of SNPs that did not emerge in main effect analyses were among the strongest findings in the interaction analyses. These include SNPs located in GRIN2B (P = 1.5 × 10,5), which encodes a subunit of the N-methyl-D-aspartate receptor channel, a key molecule in mediating age-dependent synaptic plasticity. Incorporation of logically chosen interaction parameters, such as AOS, into genetic models of substance use disorders may increase the degree of explained phenotypic variation and constitutes a promising avenue for gene discovery. [source] Psychometric performance and clinical meaningfulness of the Patient Assessment of Constipation , Quality of Life questionnaire in prucalopride (RESOLOR®) trials for chronic constipationNEUROGASTROENTEROLOGY & MOTILITY, Issue 2 2010D. Dubois Abstract Background, The Patient Assessment of Constipation,Quality of Life (PAC-QOL) is a self-reported questionnaire measuring health-related quality of life (HRQL) of constipated patients and was used as secondary endpoint in three identical double-blind, randomized, placebo-controlled Phase III clinical trials. These 12-week trials in subjects with severe chronic constipation evaluated the effects of prucalopride, a selective 5-HT4 agonist given orally once daily. Methods, To consolidate the main treatment effect results observed in the prucalopride trial populations, analyses were undertaken on the pooled data of the three trials to confirm the psychometric properties of the PAC-QOL and to provide guidance for the interpretation of the clinical significance of its scores. Key Results, The evaluation of the psychometric properties confirmed the PAC-QOL reliability, validity and responsiveness to measure the impact of chronic constipation symptoms on HRQL in the prucalopride trials. The 1-point improvement in PAC-QOL scores used as target response level for the main treatment effect analyses was validated as a relevant definition of response for treatment group comparisons. Cumulative distribution curves, drawn for each treatment group to provide more complete information on treatment effects than single minimal important difference point estimates, demonstrated consistent superior effects of prucalopride over placebo on all PAC-QOL scores. Conclusions & Inferences, The PAC-QOL questionnaire is a useful measurement tool to assess, from a patient perspective, the potential therapeutic value of chronic constipation treatments in clinical trials and, by directly reflecting the patient's own perspective on constipation and its treatment, eventually also for informing daily medical practice. [source] Association between ovocalyxin-32 gene haplotypes and eggshell quality traits in an F2 intercross between two chicken lines divergently selected for eggshell strengthANIMAL GENETICS, Issue 5 2010H. Takahashi Summary Broken and cracked eggshells contribute significantly to economic losses in the egg production industry. We previously identified ovocalyxin-32 as a potential gene influencing eggshell traits, by analysing an intercross between two parent lines developed from the same founder population by a two-way selection for eggshell strength with non-destructive deformation (DEF) conducted over 14 generations. We determined the nucleotide sequences of six ovocalyxin-32 exons in the parent individuals and analysed the association between ovocalyxin-32 and eggshell traits in the F2 individuals. We identified three haplotypes (W, M and S) of ovocalyxin-32 in the parent individuals. A mismatch amplification mutation assay was performed to distinguish six diplotype individuals (WW, MM, SS, WM, MS and WS) in the F2 population. The egg weight (EW) of SS-diplotype individuals was significantly higher than that of WW-, WM- and WS-diplotypes. Short length of the egg (SLE) of SS-diplotype individuals was significantly higher than that of WW-, WM- and MS-diplotypes. Long length of the egg (LLE) of SS-diplotype individuals was significantly higher than that of WM- and WS-diplotypes. DEF of WW-diplotype individuals was significantly higher than that of SS-, WM, MS and WM-diplotypes. Haplotypic effect analyses showed significant differences between the W-haplotype and the S-haplotypes in the EW, SLE, LLE and DEF. The DEF of M-haplotype was significantly lower than that of W- and S-haplotypes. These results suggest that S- and M-haplotypes are critical for high quality of eggshells in the F2 population. In conclusion, ovocalyxin-32 is a useful marker of eggshell traits and can be used to develop strategies for improving eggshell traits in commercial layer houses. [source] Algal toxicity of nitrobenzenes: Combined effect analysis as a pharmacological probe for similar modes of interactionENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2005Rolf Altenburger Abstract An analysis regarding the effects of the mixture toxicity of different nitrobenzenes on the reproduction of the green alga Scenedesmus vacuolatus was undertaken using the concepts of concentration addition and response addition. Using lipophilicity-based quantitative structure-activity relationship (QSAR) modeling for nitrobenzenes, the assumption is held that mononitrobenzenes may exert narcotic effects as a common type of action, whereas dinitrobenzenes show a somewhat greater toxicity. From the literature, QSARs based on quantum chemical parameters suggest that some mononitrobenzenes may be effective through additional other modes of action. The toxicity of a mixture of 14 nitrobenzenes clearly exceeds the predicted combined effects, as expected for the sum of toxic units from a uniform narcotic mode of action. Moreover, the observed combined effect is smaller than that predicted from similarly acting compounds calculated on the basis of the parameterized dose-response functions using concentration addition. Further modeling of the combined effect, joining the models of concentration addition for components with anticipated similar modes of action and of response addition for those with independent action, led us to propose that not all nitrobenzenes follow the same mode of action. This idea is in line with the hypothesis derived from quantum chemical QSAR considerations. Most interestingly, the methodology introduced here uses combined effect analysis as a pharmacological probe to test for similarity in the mode of action of mixture components. [source] Fatigue life expenditure assessment and countermeasure for turbine blades due to harmonic excitations of slip energy recovery drivesEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 8 2009Jong-Ian Tsai Abstract The long-term effect of noncharacteristic harmonic currents arising from a slip energy recovery drive (SERD) on the fatigue life expenditure in turbine-generator blades is presented in this paper. Since the SERD converter can be rated at a fraction of a motor due to its static converter cascade with the wound-rotor and with high efficiency characteristics, still the feedwater pumps (FPs) in a few power plants are driven by such an induction motor (IM) drive. However, because the frequencies of the three main harmonic terms of the recovery currents are subsynchronous and offer a probability distribution due to the adjustable speed operation, a systematic fatigue estimation approach was devised by the author to investigate the long-term impact for the low-pressure (LP) turbine blades. From the simulation results, it was found that such a long-term harmonic excitation becomes a cause of turbine blade failure for single generator connected to the SERD system, even though the amplitude of these harmonic currents is normal. By the effect analysis of uncertainty, the countermeasure for the turbine integrity was then found. Copyright © 2008 John Wiley & Sons, Ltd. [source] Citrus consumption and cancer incidence: the Ohsaki cohort studyINTERNATIONAL JOURNAL OF CANCER, Issue 8 2010Wen-Qing Li Abstract Basic research and case,control studies have suggested that citrus consumption may protect against cancer. However, the protective effect has been observed from few prospective studies. This study investigated the association of citrus consumption with cancer incidence among 42,470 Japanese adults in the Ohsaki National Health Insurance Cohort, which covered an age range of 40,79 years, and was followed up from 1995 to 2003 for all-cancer and individual cancer incidence. Citrus consumption was assessed using a self-administered questionnaire. The Cox proportional hazard model was applied to estimate relative risks (RRs) and 95% CIs. During the 323,204 person-years of follow-up, 3,398 cases were identified totally. Citrus consumption, especially daily consumption, was correlated with reduced all-cancer incidence, the RRs were 0.89 (95% CI = 0.80,0.98) for total participants, 0.86 (0.76,0.98) for males and 0.93 (0.79,1.09) for females, as well as multiple cancers at individual sites, especially pancreatic (RR = 0.62, 95% CI = 0.38,1.00) and prostate cancer (RR = 0.63, 95% CI = 0.41,0.97). Joint effect analysis showed a reduced risk of overall cancer existed only for subjects who consumed ,1 cup green tea/day (RR = 0.83, 95% CI = 0.73,0.93) as well as for males (RR = 0.83, 95% CI = 0.71,0.97) or females (RR = 0.82, 95% CI = 0.68,0.99). These findings suggest that citrus consumption is associated with reduced all-cancer incidence, especially for subjects having simultaneously high green tea consumption. Further work on the specific citrus constituents is warranted, and clinical trials are ultimately necessary to confirm the protective effect. [source] Application of failure mode and effect analysis and cause and effect analysis and Pareto diagram in conjunction with HACCP to a chocolate-producing industry: a case study of tentative GMO detection at pilot plant scaleINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 11 2007Ioannis S. Arvanitoyannis Abstract Although the application of hazard analysis critical control point in the food industry dates back to the 1970s, a more quantitative and reliable approach towards risk assessment became feasible through application of failure mode and effect analysis (FMEA) model. A tentative approach of FMEA application to a filled chocolate-producing industry was attempted in an effort to exclude the presence of genetically modified organisms (GMOs) in the final product. This is of crucial importance both from the moral (ethics) and the legislation (EC 1829/2003; EC 1830/2003; EC 18/2001) point of view. Two structured methods (preliminary hazard analysis and fault tree analysis) were used to analyse and predict the occurring failure modes in food chain system, based on the functions, characteristics and/or interactions of the ingredients or the processes, upon which the system depends. Cause and effect diagram (also known as Ishikawa, tree diagram and fishbone diagram) and Pareto diagram emerged as two very useful and effective tools towards optimising the GMO detection potential of FMEA. [source] Dynamic treatment effect analysis of TV effects on child cognitive developmentJOURNAL OF APPLIED ECONOMETRICS, Issue 3 2010Fali Huang We investigate whether TV watching at ages 6,7 and 8,9 affects cognitive development measured by math and reading scores at ages 8,9, using a rich childhood longitudinal sample from NLSY79. Dynamic panel data models are estimated to handle the unobserved child-specific factor, endogeneity of TV watching, and dynamic nature of the causal relation. A special emphasis is placed on the last aspect, where TV watching affects cognitive development, which in turn affects future TV watching. When this feedback occurs, it is not straightforward to identify and estimate the TV effect. We develop a two-stage estimation method which can deal with the feedback feature; we also apply the ,standard' econometric panel data approaches. Overall, for math score at ages 8,9, we find that watching TV during ages 6,7 and 8,9 has a negative total effect, mostly due to a large negative effect of TV watching at the younger ages 6,7. For reading score, there is evidence that watching no more than 2 hours of TV per day has a positive effect, whereas the effect is negative outside this range. In both cases, however, the effect magnitudes are economically small. Copyright © 2010 John Wiley & Sons, Ltd. [source] Consumer Substitution Effects under Full Industry EquilibriumMETROECONOMICA, Issue 1 2004Ian Steedman ABSTRACT To be of practical use comparative statics must be able to compare long-period equilibria. Such equilibria will almost never have price vectors that are proportional with respect to all prices but one,yet such price vectors are precisely those underlying the usual substitution effect analysis. We consider how this tension may be resolved. [source] Variation mode and effect analysis: an application to fatigue life predictionQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 2 2009Pär Johannesson Abstract We present an application of the probabilistic branch of variation mode and effect analysis (VMEA) implemented as a first-order, second-moment reliability method. First order means that the failure function is approximated to be linear around the nominal values with respect to the main influencing variables, while second moment means that only means and variances are taken into account in the statistical procedure. We study the fatigue life of a jet engine component and aim at a safety margin that takes all sources of prediction uncertainties into account. Scatter is defined as random variation due to natural causes, such as non-homogeneous material, geometry variation within tolerances, load variation in usage, and other uncontrolled variations. Other uncertainties are unknown systematic errors, such as model errors in the numerical calculation of fatigue life, statistical errors in estimates of parameters, and unknown usage profile. By treating also systematic errors as random variables, the whole safety margin problem is put into a common framework of second-order statistics. The final estimated prediction variance of the logarithmic life is obtained by summing the variance contributions of all sources of scatter and other uncertainties, and it represents the total uncertainty in the life prediction. Motivated by the central limit theorem, this logarithmic life random variable may be regarded as normally distributed, which gives possibilities to calculate relevant safety margins. Copyright © 2008 John Wiley & Sons, Ltd. [source] Variation Mode and Effect Analysis: a Practical Tool for Quality ImprovementQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 8 2006Per Johansson Abstract This paper describes a statistically based engineering method, variation mode and effect analysis (VMEA), that facilitates an understanding of variation and highlights the product/process areas in which improvement efforts should be targeted. An industrial application is also described to illustrate how the VMEA can be used for quality improvement purposes. Copyright © 2006 John Wiley & Sons, Ltd. [source] | |||||||||||||||||||