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At least 1,009 records · Page 56Linked to original sources
PubMed2000

[Estrogens--a breast cancer risk?].

Breast cancer is nowadays one of the most frequent cancers in female subjects. The highest risk factor is aging. Early age at first full-time pregnancy is in many studies associated with a reduced risk of breast cancer. Other risk factors are obesity, early menarche and late menopause. According to recent epidemiological studies and a reanalysis of all prospective studies longtime ERT and HRT are also associated with a slightly higher incidence of breast cancer. This higher incidence is, however, very limited and not associated with a higher mortality because only low grade, slowly progressing, receptor positive cancers are increased.

Age Factors↗
PubMed2002

[Hormone replacement and breast carcinoma].

This review discusses the effect of Oestrogens, Progestagens, Tibolone, Raloxifene and Phytooestrogens in postmenopausal women on the breast. Epidemiological statisticians are only speaking of a clinical significance if the relative risk is half (< 0.05) or doubled (> 2.0). All published data from observational studies or from important meta- and reanalyses concerning the relative risk of breast cancer in women using postmenopausal hormone therapy are within these limits and clearly below the risk observed in young smokers. The relative risk for breast cancer observed in the Womens Health Initiative (WHI) stays within these limits too, in women treated by a fix Oestrogen-Progestagen combination. However, in the WHI, there was no increase of the relative risk for breast cancer in women using oestrogens alone. The risk for breast cancer rises in parallel to the duration of the hormone treatment. The risk for hormone users to suffer from breast cancer does not increase earlier than 4-5 years after the start of the therapy. An important reanalysis reports, that after 5 years of hormone use, a breast cancer is diagnosed in 2 additional women out of 1000 (47 instead of 45 women). The absolute risk should be indicated in addition to the relative risk because, for non-specialists, the exclusive indication of the relative risk might be misleading. Following the results from the WHI and from some other, older studies, the relative risk for breast cancer might be higher in women taking an oestrogen-progestagen combination than in women using oestrogens alone. Experimental and preliminary clinical data on Tibolone and Raloxifene do not show a negative effect on breast tissue. However, if Tibolone and Raloxifene as well as Phytooestrogens possess a protective activity remains open because prospective randomized long-term clinical studies are still missing.

Adult↗
PubMed2006

What makes multiplication facts difficult. Problem size or neighborhood consistency?

Two current models of arithmetic fact retrieval, the network interference theory (NIT; Campbell, 1995) and the interacting neighbors (IN) model (Verguts & Fias, 2005a), predict that errors in simple multiplication should be more probable, if they include the same digit as the correct result (i.e., if they are "consistent," compared with "inconsistent" errors). In a reanalysis of error data originally reported by Campbell (1997), we provide first empirical evidence for this prediction. Furthermore, these results support the notion of different quantity representations for decades and units as proposed by Nuerk, Weger, and Willmes (2001). However, the NIT and IN-model differ in their explanations of the problem-size effect, a hallmark finding robustly observed in arithmetic fact retrieval. Only the IN-model predicts that a correct answer's neighborhood consistency can fully account for the problem-size effect, which was confirmed in our analysis.

Attention↗
PubMed1995

Photochemistry of Triton's atmosphere and ionosphere.

The photochemistry of 32 neutral and 21 ion species in Triton's atmosphere is considered. Parent species N2, CH4, and CO (with a mixing ratio of 3 x 10(-4) in our basic model) sublime from the ice with rates of 40, 208, and 0.3 g/cm2/b.y., respectively. Chemistry below 50 km is driven mostly by photolysis of methane by the solar and interstellar medium Lyman-alpha photons, producing hydrocarbons C2H4, C2H6, and C2H2 which form haze particles with precipitation rates of 135, 28, and 1.3 g/cm2/b.y., respectively. Some processes are discussed which increase the production of HCN (by an order of magnitude to a value of 29 g/cm2/b.y.) and involve indirect photolysis of N2 by neutrals. Reanalysis of the measured methane profiles gives an eddy diffusion coefficient K = 4 x 10(3) cm2/s above the tropopause and a more accurate methane number density near the surface, (3.1 +/- 0.8) x 10(11) cm-3. Chemistry above 200 km is driven by the solar EUV radiation (lambda < 1000 angstroms) and by precipitation of magnetospheric electrons with a total energy input of 10(8) W (based on thermal balance calculations). The most abundant photochemical species are N, H2, H, O, and C. They escape with the total rates of 7.7 x 10(24) s-1, 4.5 x 10(25) s-1, 2.4 x 10(25) s-1, 4.4 x 10(22) s-1, and 1.1 x 10(24) s-1, respectively. Atomic species are transported to a region of 50-200 km and drive the chemistry there. Ionospheric chemistry explains the formation of an E region at 150-240 km with HCO+ as a major ion, and of an F region above 240 km with a peak at 320 km and C+ as a major ion. The ionosphere above 500 km consists of almost equal densities of C+ and N+ ions. The model profiles agree with the measured atomic nitrogen and electron density profiles. A number of other models with varying rate coefficients of some reactions, differing properties of the haze particles (chemically passive or active), etc., were developed. These models show that there are four basic unknown values which have strong impacts on the composition and structure of the atmosphere and ionosphere. These values and their plausible ranges are the CO mixing ratio fco = 10(-4)-10(-3), the magnetospheric electron energy input (1 +/- 0.5) x 10(8) W, the rate coefficient of charge-exchange reaction N2(+) + C k = 10(-11)-10(-10) cm3/s, and the ion escape velocity Vi approximately equal to 150 cm/s.

Atmosphere↗
PubMed2000

Pocket 4 in the HLA-DRB1 antigen-binding groove: an association with atopy.

BACKGROUND: Many studies have attempted to identify an association between HLA genes and atopy, given the role of HLA molecules in the regulation of the immune response. In the case of house-dust mites, it is difficult to find an association with a particular HLA allele, due to the complexity of the allergen. The objective was to investigate whether HLA-DRB1 functional groups are better correlated with the atopic disease in our population than DRB1 alleles. METHODS: The method was reanalysis of the HLA-DRB1 data of a previous case/ control study. RESULTS: The "Dr" group was found to be associated with the atopic disease in our population. CONCLUSIONS: Grouping HLA-DRB1 alleles into functional categories may assist in the search for predictive factors in relation to atopic disease.

Adult↗
PubMed2000

Sequential re-analysis of a phase-III clinical trial in non-small cell lung cancer.

This paper presents a reanalysis of a randomized clinical trial conducted by the Cancer and Leukemia Group B (CALGB, Bethesda, MD, USA). This trial found a significant benefit of combination chemotherapy followed by irradiation (CTRT) in comparison to radiotherapy alone (RT) for the treatment of nonsmall cell lung cancer. The validity of the results obtained and the decision to terminate taken by the CALGB, were assessed using sequential methods. The reliability and efficiency of sequential methods were also assessed for this study. Two sequential designs were used: the triangular and the restricted procedure. Initial analyses were conducted with the data from patients actually recruited, adjusting for important prognostic variables at any interim analysis. As a confirmatory technique, a continuation of the trial was simulated, sampling extra patients under the assumption of no treatment difference, preserving the effect of the prognostic variables. Using the results from the 155 patients recruited by the CALGB (88 deaths at termination and 136 after follow-up), the sample path stayed within the continuation region of both sequential designs considered. An underpowered sequential analysis showed significant superiority of CTRT over RT (95% confidence interval (95% CI) 0.50-0.96, p=0.03 for the triangular; 95% CI 0.37-0.88, p=0.01 for the restricted procedure). Conventional analysis of the follow-up data also showed significant superiority of CTRT. The trial extended with simulated data ended at 60 months with 251 patients (178 deaths), showing significant superiority of CTRT under both designs (95% CI for hazard ratio 0.55-0.97). The two sequential procedures would have led to the same conclusion as that reached by the Cancer and Leukemia Group B, still achieving considerable savings in patients recruited and time over the conventional design. The data simulated under the rather conservative null hypothesis did not reverse the positive result claimed by the Cancer and Leukemia Group B.

Carcinoma, Non-Small-Cell Lung↗
PubMed1999

Conversion of plaque-area measurements to plaque index scores. An assessment of variation and discriminatory power.

Plaque areas recorded graphically or photographically provide a permanent record of plaque accumulations on teeth at a moment in time. As such, these records could be re-evaluated and converted into other index scores. The purpose of this study was to determine the reproducibility of scoring a plaque index from previously recorded plaque areas and to compare such scores with the original scores of the same index. A randomised blind, crossover study comparing 5 treatments for plaque inhibition scored by plaque area and index was chosen. 2 examiners, the original scorer PRH and another, NC, 2x scored the plaque area tooth charts according to the criteria of the plaque index system used in the original study. Standard deviations of the differences showed intra-examiner repeatability to be high particularly for the original examiner. Inter-examiner reproducibility for the original index scores was considered good but less than for intra-examiner repeatability. Correlation coefficients were complimentary to the differences analysis, being very high within examiners and less high for between examiners and original and rescored index. Separation between distributions of plaque area measurements for consecutive values of the index were particular good for scores 2 versus 3 and 3 versus 4 and less good for 1 versus 2 and 4 versus 5. Reanalysis of the study for treatment differences using rescored data revealed a similar level of significance as using the original data. Rescored index had similar discriminatory power for the study as plaque area and original plaque index when both were derived from the same buccal tooth surfaces. However, discriminatory power was less by comparison with original plaque index derived from the buccal surfaces of all teeth. It is concluded that plaque area provides a permanent record of plaque distribution which can be converted into index data at a later date. Such data collection could make possible comparisons between studies using different indices.

Cross-Over Studies↗
PubMed1991

Implications of therapist effects for the design and analysis of comparative studies of psychotherapies.

Technical reasons are presented as to why therapist should be included as a random design factor in the nested analysis of (co)variance (AN[C]OVA) design commonly used in psychotherapy research. Incorrect specification of the ANOVA design can, under some circumstances, result in incorrect estimation of the error term, overly liberal F ratios, and an unacceptably high risk of Type I errors. Review of studies indicates that the great majority of investigators continue to ignore this issue. Computer simulation studies revealed that considerable bias can be introduced by not specifying therapist as a random term. Finally, a reanalysis is presented of data from 10 psychotherapy outcome studies that indicated that therapist effects vary considerably and at times can be large. More recent studies that implement better quality controls appear to demonstrate less variance due to therapist. The implications of these results for the design of future studies are discussed.

Analysis of Variance↗
PubMed1992

Deterioration of intellect among children surviving leukemia: IQ test changes modify estimates of treatment toxicity.

This study assessed the association of young age at treatment, cranial irradiation, and time since treatment with intellectual deterioration among 49 long-term survivors of childhood leukemia. Ss had been randomized to receive low-dose cranial radiation therapy or high-dose chemotherapy. Longitudinal assessments of intellect were conducted. No significant effects of treatment group or age at treatment were detected. A small but statistically significant decline in mean full-scale IQ was noted over time (M = -3.6). Reanalysis with IQ test version included as a covariate eliminated IQ declines found initially. Results suggest (a) that there has been reduced toxicity of these methods of treatment and (b) that the magnitude and direction of error introduced by changing tests may approximate the magnitude of adverse effects on IQ from treatment.

Age Factors↗
PubMed1976

Kinesthetic aftereffect and personality: a case study of issues involved in construct validation.

Kinesthetic Aftereffect (KAE), once a promising personality index, has been abandoned by many investigators because of poor retest reliability and intermittent validity. In challenging this current consensus, we argue that (a) first-session KAE is valid; (b) poor retest reliability simply reflects later-session bias; (c) hence, multisession studies should not be used to assess validity without taking this bias into account. Those recent studies which failed to support KAE validity were each multisession in design. If our bias contention is correct, these studies should be ignored, and the claim of intermittent validity is thus rebutted. Reanalysis of the most recent major multisession, nonsupportive validity study indicates (a) Session 1 validity, (b) later-session bias, and (c) later-session valdiity when multisession scores are combined to avoid bias. Thus, KAE validly measures personality.

Humans↗
PubMed1977

Behavior change following self-confrontation: a test of the value-mediation hypothesis.

This study presents a reanalysis of data from Rokeach's self-confrontation experiments using path analytic techniques. Contrary to Rokeach's interpretations, findings indicate that behavior changes following self-confrontation are not primarily mediated through changes in value priorities. Rather, the available data suggest that the self-confrontation process involves the resolution of inconsistencies between behaviors and self-conceptions that are revelaed during the treatment session. The authors interpret these findings within the framework of Rokeach's general theory of self-disatisfaction and cognitive-behavioral change. Suggestions for future directions in self-confrontation research are offered.

Attitude↗
PubMed1988

Affine distortions of pictorial space: some predictions for Goldstein (1987) that La Gournerie (1859) might have made.

Goldstein (1987) studied the perception of pictures seen from the front and the side. Several distinctions arose from his results and analysis, but only one is central to the reanalysis presented here: The perceived orientation of objects within a picture with respect to the external world is a function of viewer position in front of the picture. For example, the eyes of a portrait subject appear to follow an observer who moves around a gallery. Viewed from many positions, such objects can be said to rotate, following a mobile viewer. Goldstein called this the differential rotation effect because those objects that point directly out of the picture (at 90 degrees) rotate most; those pointing at other angles rotate in decreasing amounts. Goldstein offered no theoretical model and little in the way of explanation for this effect. This Observation offers a model based on the affine geometry and the analyses of La Gournerie (1859). This analysis transforms pictorial space (the space behind a photograph or representational picture) by shears, compressions, and dilations according to the viewpoint of the observer in relation to the composition point of the picture. These effects account for Goldstein's differential rotation effect quite well.

Depth Perception↗
PubMed1996

Weight perception and the haptic size-weight illusion are functions of the inertia tensor.

The complex effects of mass and volume on weight perception (e.g., the size-weight illusion) were hypothesized to follow simply from invariants of rotational dynamics. In Experiments 1-3, the rotational inertia of wielded, occluded objects was varied independently of mass, size, and torque. Perceived heaviness depended only on rotational intertia. Reanalysis of J. C. Stevens and L. L. Rubin's (1970) study revealed that size's influence on weight perception depends on specific patterns of the eigenvalues of the inertia tensor. These patterns were simulated in Experiments 4-6 with objects of fixed mass, volume, and visible size. Perceived heaviness decreased and increased, respectively, over object sets with the eigenvalue patterns of (a) constant mass, increasing volume and (b) increasing mass, constant volume. Weight perception and the size-weight illusion depend on stimulus invariants, not inference.

Female↗
PubMed2000

Serial processing in reading aloud: reply to Zorzi (2000).

K. Rastle and M. Coltheart (1999; see also M. Coltheart & K. Rastle, 1994) reported data demonstrating that the cost of irregularity in reading aloud low-frequency exception words is modulated by the position of the irregularity in the word. They argued that these data implicated a serial process and falsified all models of reading aloud that operate solely in parallel, a conclusion that M. Zorzi (2000) challenged by successfully simulating the position of irregularity effect with such a model. Zorzi (2000) further claimed that a reanalysis of K. Rastle and M. Coltheart's (1999) data demonstrates sensitivity to grapheme-phoneme consistency (which he claimed was confounded across the position of irregularity manipulation) rather than the use of a serial process. Here, the authors argue that M. Zorzi's (2000) reanalyses were inappropriate and reassert that K. Rastle and M. Coltheart's (1999) findings are evidence for serial processing.

Humans↗
PubMed2001

Attentional momentum does not underlie the inhibition of return effect.

J. Pratt, T. M. Spalek, and F. Bradshaw (1999) recently proposed that attentional momentum is the mechanism underlying the inhibition of return (IOR) effect. They suggested that momentum associated with an attentional movement away from a peripherally cued location and toward an uncued opposite location is essential and fundamental to the finding of an IOR effect. Although it is clear from the present study and from a reanalysis of data from Pratt et al. that response time can be facilitated at an uncued opposite location, this putative effect of attentional momentum is neither robust nor reliable. First, it occurs for only a minority of participants. Second, it occurs in only a subset of the cued display positions. And finally, it is uncorrelated with the occurrence of IOR. Together the data indicate that the attentional momentum hypothesis is an overgeneralization and that it does not underlie the robust and reliable IOR effect.

Attention↗
PubMed1985

Memorability as a measure of processing: a unit analysis of prose and list learning.

The percentage of subjects recalling each unit in a list or prose passage is considered as a dependent measure. When the same units are recalled in different tasks, processing is assumed to be the same; when different units are recalled, processing is assumed to be different. Two collections of memory tasks are presented, one for lists and one for prose. The relations found in these two collections are supported by an extensive reanalysis of the existing prose memory literature. The same set of words were learned by 13 different groups of subjects under 13 different conditions. Included were intentional free-recall tasks, incidental free recall following lexical decision, and incidental free recall following ratings of orthographic distinctiveness and emotionality. Although the nine free-recall tasks varied widely with regard to the amount of recall, the relative probability of recall for the words was very similar among the tasks. Imagery encoding and recognition produced relative probabilities of recall that were different from each other and from the free-recall tasks. Similar results were obtained with a prose passage. A story was learned by 13 different groups of subjects under 13 different conditions. Eight free-recall tasks, which varied with respect to incidental or intentional learning, retention interval, and the age of the subjects, produced similar relative probabilities of recall, whereas recognition and prompted recall produced relative probabilities of recall that were different from each other and from the free-recall tasks. A review of the prose literature was undertaken to test the generality of these results. Analysis of variance is the most common statistical procedure in this literature. If the relative probability of recall of units varied across conditions, a units by condition interaction would be expected. For the 12 studies that manipulated retention interval, an average of 21% of the variance was accounted for by the main effect of retention interval, 17% by the main effect of units, and only 2% by the retention interval by units interaction. Similarly, for the 12 studies that varied the age of the subjects, 6% of the variance was accounted for by the main effect of age, 32% by the main effect of units, and only 1% by the interaction of age by units.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1985

Discontinuity in cognitive skill.

Skill at reading geometrically transformed text improves as a function of practice across pages. A belief in continuity of learning must suppose a proportionate improvement in skill within pages. We tested for continuity of learning by comparing performance within pages with performance between pages, varying timing of text presentation and quantity of text presented for the purpose. Reanalysis of some published data and three new experiments indicated that skill is acquired continuously as a function of practice but is expressed discontinuously. We conjecture that the expression of skill requires perceptual segregation of tasks into task units to which skill is transferred, whereas acquisition of competence occurs as a strict function of practice.

Adult↗
PubMed1990

Use of verb information in syntactic parsing: evidence from eye movements and word-by-word self-paced reading.

We investigated whether readers use verb information to aid in their initial parsing of temporarily ambiguous sentences. In the first experiment, subjects' eye movements were recorded. In the second and third experiments, subjects read sentences by using a noncumulative and cumulative word-by-word self-paced paradigm, respectively. The results of the first two experiments supported Frazier and Rayner's (1982) garden-path model of sentence comprehension: Verb information did not influence the initial operation of the parser. The third experiment indicated that the cumulative version of the self-paced paradigm is not appropriate for studying on-line parsing. We conclude that verb information is not used by the parser to modify its initial parsing strategies, although it may be used to guide subsequent reanalysis.

Adult↗