Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Reanalysis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,117 records · Page 62Linked to original sources
PubMed1998

Mistakes around the clock: errors in memory for the orientation of numerals.

Recent research has demonstrated that when participants are required to draw from memory a standard clock with numbers represented by Roman numerals, they typically misrepresent the four as "IV" rather than as the correct "IIII." Participants do not make this mistake when they simply copy the clock while it remains in full view. A reanalysis of the data presented by Richards, French, and Harris (1996) is reported in which we investigated the representation of the orientation of the Roman numerals on the clockface and found that participants in the memory conditions (surprise and forewarned) were more likely than participants in the copy (control) condition to draw the numerals vertically rather than in their correct centripetal orientation. In addition, we found this error was even more likely to occur for participants when they had no warning that a memory task would take place.

Adult↗
PubMed1987

The semantics of success: do masturbation exercises lead to partner orgasm?

Do masturbation exercises assigned in preorgasmic women's groups enable previously nonorgasmic women to achieve orgasms during partner sex? Studies by Wallace and Barbach and Ersner-Hershfield and Kopel report encouraging partner orgasmic success rates of 87% and 82%, respectively, and these figures are commonly cited in reviews of the literature. I argue that these rates are misleading because they reflect overly liberal research definitions of "nonorgasmic," "orgasmic success," and "partner orgasm." A reanalysis of Ersner-Hershfield and Kopel's data using more stringent and intuitive criteria yields a partner success rate at 10 weeks after termination of 20% (or 47%, if women who require the use of a vibrator to have orgasm during partner sex are included as successes), as opposed to their original figure of 82%. These results suggest that masturbation training in preorgasmic women's groups is not the treatment of choice for most previously nonorgasmic women seeking partner orgasm. They also illustrate how different ideological conceptions of the meaning of sex can lead to different definitions of outcome categories and different evaluations of the same data.

Coitus↗
PubMed1993

Suppression of colonic cancer by dietary phytic acid.

Large differences exist between human populations in the frequency of colonic cancer. Epidemiological evidence indicates that these differences are strongly influenced by country of residence, and a negative correlation has been found between the fiber content of the diet and frequency of colonic cancer. This has prompted the hypothesis that high-fiber diets are in some way protective. However, reanalysis of the dietary data provides equally strong support for the hypothesis that the protective element may be phytic acid (inositol hexaphosphate). This heat- and acid-stable substance is present in high concentration in many food items, including cereal grains, nuts, and seeds. Phytic acid forms chelates with various metals and suppresses damaging iron-catalyzed redox reactions. Inasmuch as colonic bacteria have been shown to produce oxygen radicals in appreciable amounts, dietary phytic acid might suppress oxidant damage to intestinal epithelium and neighboring cells. Indeed, rapidly accumulating data from animal models indicate that dietary supplementation with phytic acid may provide substantial protection against experimentally induced colonic cancer. Should further investigations yield additional support for this hypothesis, purposeful amplification of dietary phytic acid content would represent a simple method for reducing the risk of colonic carcinogenesis.

Colonic Neoplasms↗
PubMed2005

Variation and homogeneity in affective responses to physical activity of varying intensities: an alternative perspective on dose-response based on evolutionary considerations.

A model for systematic changes in patterns of inter-individual variation in affective responses to physical activity of varying intensities is presented, as a conceptual alternative to the search for a global dose-response curve. It is theorized that trends towards universality will emerge in response to activities that are either generally adaptive, such as moderate walking, or generally maladaptive, such as strenuous running that requires anaerobic metabolism and precludes the maintenance of a physiological steady state. At the former intensity the dominant response will be pleasure, whereas at the latter intensity the dominant response will be displeasure. In contrast, affective responses will be highly variable, involving pleasure or displeasure, when the intensity of physical activity approximates the transition from aerobic to anaerobic metabolism, since activity performed at this intensity entails a trade-off between benefits and risks. Preliminary evidence in support of this model is presented, based on a reanalysis of data from a series of studies.

Adaptation, Physiological↗
PubMed2003

Learning about cues in their absence: evidence from flavour preferences and aversions.

A simple behavioural task may involve the presentation of two or more stimuli. Any learning that takes place in such a situation may be analysed in terms of the formation of an association between the central representations of those stimuli. Presumably performance based on this learning can occur because presentation of one stimulus will then activate the representations of other stimuli that were previously presented with it. To examine the role that these representations play in learning in and of themselves requires that the stimuli themselves are absent. A review of a number of flavour preference and aversion studies indicates that an associatively activated stimulus representation can support learning that is both similar to and the opposite of that maintained by the presentation of the stimulus itself. Which occurs is dependent upon the nature of the reinforcer and the temporal relationships between the training events. Although this pattern of results appears suggestive of separate learning rules, a reanalysis raises the possibility of an explanation in terms of a single associative system.

Association Learning↗
PubMedDate not supplied

Monkey perirhinal cortex is critical for visual memory, but not for visual perception: reexamination of the behavioural evidence from monkeys.

Overdependence on discrimination learning paradigms to assess the function of perirhinal cortex has complicated understanding of the cognitive role of this structure. Impairments in discrimination learning can result from at least two distinct causes: (a) failure to accurately apprehend and represent the relevant stimuli, or (b) failure to form and remember associations between stimulus representations and reward. Thus, the results of discrimination learning experiments do not readily differentiate deficits in perception from deficits in learning and memory. Here I describe studies that do dissociate learning and memory from perception and show that perirhinal cortex damage impairs learning and/or memory, but not perception. Reanalysis and reconsideration of other published data call into further question the hypothesis that the monkey perirhinal cortex plays a critical role in visual perception.

Animals↗
PubMedDate not supplied

A comparison of the OnTrak Testcup-5 to laboratory urinalysis among arrestees.

Research studies that collect urine specimens to measure recent drug use have traditionally sent the specimens to laboratories for analysis. A new method of urinalysis-instant urine testing-may offer a quicker, equally accurate alternative to laboratory assays. To date, however, no studies have explored the efficacy of instant urine technology with individuals under criminal justice supervision. To address this limitation, the authors administered a single instant urine test-the OnTrak Testcup-5-to 136 adult male arrestees surveyed through Maryland's Substance Abuse Need for Treatment among Arrestees (SANTA) study. The specimens were subsequently shipped to an independent laboratory for reanalysis. Analyses indicate high agreement between the two techniques for marijuana, cocaine, and heroin. Potential uses for the OnTrak Testcup-5 are discussed.

Adolescent↗
PubMed2004

Combating substance abuse with ibogaine: pre- and posttreatment recommendations and an example of successive model fitting analyses.

Ibogaine is an indole alkaloid derived from the root bark of the African shrub Tabernan the iboga and it has been used for many years as a medicinal and ceremonial agent in West Central Africa. Furthermore, both anecdotal observations and recent studies suggest that ibogaine alleviates withdrawal symptoms and reduces drug cravings. Although ibogaine articles typically include information bearing on the duration of drug abstinence following treatment, little if any attention is given to the psychological and environmental factors that might facilitate a positive treatment outcome. Hence, a major purpose of the present review is to suggest a number of theory-driven, pretreatment and posttreatment recommendations that have good potential for enhancing ibogaine's effectiveness. The second major purpose of this review is to demonstrate, through a reanalysis of previously published results, the utility of conducting successive model fitting analyses on ibogaine treatment data. Such analyses are useful for determining both the strength and form of the association between pre-ibogaine treatment variables and post-ibogaine treatment outcomes. Finally, in order to facilitate future quantitative reviews, the authors recommend that a minimum set of patient- and treatment-related variables be included in all ibogaine publications involving human participants.

Adult↗
PubMed2004

Does stage at diagnosis explain the difference in survival after breast cancer in Denmark and Sweden?

Breast cancer survival differs 9 percentage points between the neighbouring countries of Denmark and Sweden. The authors' aim was to analyse whether this was caused by early detection in Sweden. The extent of disease and outcome was compared in two population-based breast cancer cohorts in 1983-1989. Breast cancer management was decentralized in Denmark without mammography screening whereas treatment in Sweden was centralized and the population partly screened. Ten- and 15-year relative survival was 15% and 6% higher in Sweden (p<0.001) with corresponding differences in crude and disease-specific survival. Stage distribution was significantly more favourable in the Swedish cohort. In multivariate analysis age, tumour size, extent of axillary surgery, and spread affected survival; however, the impact of region persisted (p<0.001). Reanalysis without screening-detected patients only slightly affected the impact of region. It was concluded that early detection had significant impact on survival but other regional differences might be of importance.

Adult↗
PubMed2005

Determination of commonly used herbicides in surface water using solid-phase extraction and dual-column HPLC-DAD.

The present study describes the application of different solid-phase extraction techniques for the extraction, separation, and quantitative determination of 10 commonly used herbicides with different chemical structures (chlorsulfuron, diuron, bentazone, linuron, chlorpropham, fenoxoprop-ethyl, MCPA, diclofop-methyl, fluazifop-butyl, trifluraline) in water. Octadecyl (C(18)) Empore extraction disks, octadecyl (C(18)), and stryene divinylbenzene (SDB) Bond Elut Env cartridges were compared for solid-phase extraction efficiency. Herbicides were separated and quantified by reversed-phase high performance liquid chromatography with diode-array detection (HPLC-DAD) with simultaneous separation on two columns of differing polarity (C(18) and CN) to confirm identification. Analytical separation was performed simultaneously on C(18) and CN columns. Reanalysis of the sample extracts on a (cyano) CN column were used to confirm the identity of these compounds. Method optimization and validation parameters were presented in this work. Recoveries varied from 76.0% to 99.0% for C(18) disks, from 75.1% to 100.0% for C(18) cartridges, and from 54.0% to 98.0% for SDB cartridges over concentrations at 0.025--0.4 microg L(-1). The limits of detection were 0.012--0.035 microg L(-1).

Chromatography, High Pressure Liquid↗
PubMed1990

Adults' word recall and word repetition.

This experiment investigated age group differences in working memory by examining the effects of word length on adults' recall span and repetition rate. College students and adults, 60 to 94 years of age, recalled lists of one-, two-, or three-syllable words and repeated aloud pairs of one-, two- or three-syllable words. Word recall spans and word repetition rates were computed. Main effects of age group and word length were obtained on both measures, although the interactions were not significant. A second analysis examined the relationship between individuals' recall span and their repetition rate. Across all age groups combined, recall span was a linear function of repetition rate and accounted for 25 percent of the variance on the recall task. A reanalysis of the word repetitions revealed that older adults' word durations and inter-word pauses are longer than young adults'.

Adult↗
PubMed2000

Life Stage, Alcohol Consumption Patterns, Alcohol-Related Consequences, and Gender.

This paper presents findings from a European collaborative study. A common framework for reanalysis of existing data was devised. Alcohol-related problems encountered were classified as "internal" and "external." Logistic regression analyses were then conducted to predict lifetime presence of any internal problem, any external problem, and any problem at all. The predictor variables were gender, life stage (corresponding roughly to young, middle and older age), past year's drinking level in four categories of grams of alcohol per month, and past year's "binge" drinking. All four predictor variables were associated with the presence of alcohol-related problems, with women and retired people having fewer problems and heavy drinkers and binge drinkers having more. At all levels of alcohol consumption, men were more likely than women to experience at least one adverse consequence. Internal problems were more common than external problems. Country differences are discussed and recommendations are made for further studies.

Journal Article↗
PubMed1988

Identification of stress buffers.

A large amount of research has been published about the role of intervening variables as buffers for the effects of stress precursors on adverse stress impacts. A review revealed that most of these reports focused on single candidates or a subjectively selected constellation of variables using narrow definitions of both precursors and impacts with a variety of statistical procedures. A set of 22 variables was investigated to determine the relative importance of each as a stress buffer, using broadened measures for precursors and impacts. Discriminant analysis with t-test follow-up of data from 668 normally functioning men and women indicated the existence of 7 strong and 7 moderate buffers and a differential effect by sex. Reanalysis, comparing the results from other statistical procedures, concluded that there were 4 "true" buffers: sense of competence, exercise pattern, sense of purpose, and leisure activity. Eleven of the 22 demonstrated main effects independent of stress. This study discusses the importance of using standard statistical procedures with comprehensive measures in order to further knowledge about the human stress process.

Adult↗
PubMed2006

The factor structure of the CVLT-C in pediatric epilepsy.

The current study used archival data to evaluate the fit of six latent variable models, originally generated by Donders (1999), for the California Verbal Learning Test-Children's Version (CVLT-C; Delis, Kramer, Kaplan, & Ober, 1994) in a large (N = 289) sample of pediatric epilepsy cases presenting at three tertiary treatment centers. Using confirmatory factor analysis, we found that a model including factors of Attention Span, Learning Efficiency, Free Delayed Recall, Cued Delayed Recall, and Inaccurate Recall demonstrated the best relative fit for our data. These findings are consistent with those reported by Donders (1999) in his reanalysis of the CVLT-C standardization sample data, supporting the validity of this factorial model in pediatric epilepsy populations.

Adolescent↗
PubMed2005

Platelet aggregation in whole blood is a paradoxical predictor of ischaemic stroke: Caerphilly Prospective Study revisited.

The Caerphilly Prospective Study demonstrates a paradoxical association of increased ischaemic stroke risk with decreased whole blood adenosine diphosphate (ADP) induced platelet sensitivity. A reanalysis of this association examines whether other haematological indices and prevalent disease at baseline may explain this finding. There were 1506 men free of clinical cardiovascular disease at baseline, with 85 men manifesting a first ischaemic stroke event over 8.3 years of follow-up in this population-based prospective cohort study. Using two different approaches, the paradoxical findings are confirmed and associations are slightly stronger after accounting for red cell, platelet, and white cell indices. A U-shaped relation of stroke with platelet count is noted. These findings are consistent with the existence of sub-clinical endothelial disease and compensatory mechanisms down-regulating ADP-induced aggregation sensitivity. They support an allostasis model of causality for understanding the paradox. A public health approach to prevention could have measurable impact if intervention strategies can be developed to alter early stages of disease appropriate to such mechanisms of causation.

Adenosine Diphosphate↗
PubMed2001

Micronucleus assay in vivo provides significant prognostic information in human cervical carcinoma; the updated analysis.

PURPOSE: Reanalysis after a 5-year follow-up previously presented relationships between spontaneous and radiation-induced micronucleus frequencies in tumour cells and the clinical outcome of patients with advanced stages (II B-IV B) of cervix carcinomas treated with radiotherapy. MATERIALS AND METHODS: Spontaneous and induced in vitro and in vivo micronucleus frequencies were determined and related to clinical parameters. Data were analysed by the univariate Kaplan-Meier method and multivariate Cox proportional hazards model. RESULTS: In univariate analysis stage, spontaneous micronucleus frequency before radiotherapy (MNSP) and per cent increment of micronucleus level in vivo after 20 Gy in relation to spontaneous pretreatment level were statistically significant predictors of 5-year recurrence-free, disease-free and overall survival. Neither micronucleus frequency (MN/BNC at 2 Gy) nor proliferating fraction (%BNC at 0 Gy) estimated in vitro (in primary culture) were related to radiotherapy outcome. The age of patients was not associated with clinical results. Multivariate analysis demonstrated that the clinical stage of disease, the high frequency of spontaneous micronuclei and low-induced micronucleus frequency were independent and significantly unfavourable predictive factors for disease-free and overall survival. But for local control, only high MNSP and low-induced MN frequency were significant negative predictive variables. CONCLUSIONS: A high frequency of micronuclei before radiotherapy and a slight increase of micronucleus frequency during radiotherapy measured after 10 fractions of 2 Gy were independent on stage, statistically significant adverse predictors of clinical outcome in cervical carcinoma patients treated with radiotherapy.

Adult↗
PubMed2000

Is daily mortality associated specifically with fine particles? Data reconstruction and replication of analyses.

In 1996, Schwartz, Dockery, and Neas reported that daily mortality was more strongly associated with concentrations of PM2.5 than with concentrations of larger particles (coarse mass [CM]) in six U.S. cities ("original paper"/"original analyses"). Because of the public policy implications of the findings and the uniqueness of the concentration data, we undertook a reanalysis of these results. This paper presents results of the reconstruction of these data and replication of the original analyses using the reconstructed data. The original investigators provided particulate air pollution data for this paper. Daily weather and daily counts of total and cause-specific deaths were reconstructed from original public records. The reconstructed particulate air pollution and weather data were consistent with the summaries presented in the original paper. Daily counts of deaths in the reconstructed data set were lower than in the original paper because of restrictions on residence and place of death. The reconstruction process identified an administrative change in county codes that led to higher numbers of deaths in St. Louis. Despite these differences in daily counts of deaths, the estimated effects of particulate air pollution from the reconstructed dataset, using analytic methods as described in the original paper, produced combined effect estimates essentially equivalent to the originally published results. For example, the estimated association of a 10 micrograms/m3 increase in 2-day mean particulate air pollution on total mortality was 1.3% (95% confidence interval [CI] 0.9-1.7%, t = 6.53) for PM2.5 based on the reconstructed dataset, compared to the originally reported association of 1.5% (95% CI 1.1-1.9%, t = 7.41). For coarse particles, the estimated association from the reconstructed dataset was 0.4% (95% CI -0.2-0.9%, t = 1.43) compared to the originally reported association of 0.4% (95% CI -0.1-1.0%, t = 1.48). These results from the reconstructed data suggest that the original results reported by Schwartz, Dockery, and Neas were essentially replicated.

Adolescent↗
PubMed2005

Hidden likelihood support in genomic data: can forty-five wrongs make a right?

Combined analysis of multiple phylogenetic data sets can reveal emergent character support that is not evident in separate analyses of individual data sets. Previous parsimony analyses have shown that this hidden support often accounts for a large percentage of the overall phylogenetic signal in cladistic studies. Here, reanalysis of a large comparative genomic data set for yeast (genus Saccharomyces) demonstrates that hidden support can be an important factor in maximum likelihood analyses of multiple data sets as well. Emergent signal in a concatenation of 106 genes was responsible for up to 64% of the likelihood support at a particular node (the difference in log likelihood scores between optimal topologies that included and excluded a supported clade). A grouping of four yeast species (S. cerevisiae, S. paradoxus, S. mikatae, and S. kudriavzevii) was robustly supported by combined analysis of all 106 genes, but separate analyses of individual genes suggested numerous conflicts. Forty-eight genes strictly contradicted S. cerevisiae + S. paradoxus + S. mikatae + S. kudriavzevii in separate analyses, but combined likelihood analyses that included up to 45 of the "wrong" data sets supported this group. Extensive hidden support also emerged in a combined likelihood analysis of 41 genes that each recovered the exact same topology in separate analyses of the individual genes. These results show that isolated analyses of individual data sets can mask congruence and distort interpretations of clade stability, even in strictly model-based phylogenetic methods. Consensus and supertree procedures that ignore hidden phylogenetic signals are, at best, incomplete.

Classification↗