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At least 595 records · Page 33Linked to original sources
PubMed1998

Event-related brain potentials and case information in syntactic ambiguities.

In an ERP study, German sentences were investigated that contain a case-ambiguous NP that may be assigned accusative or dative case. Sentences were disambiguated by the verb in final position of the sentence. As our data show, sentences ending in a verb that assigns dative case to the ambiguous NP elicit a clear garden-path effect. The garden-path effect was indicated by a broad centro-posterior negative shift that occurred between 300 and 900 msec after the dative-assigning verb was presented. No enhanced P600 following the misanalysis was observed. Noun phrases whose case ambiguity was resolved in favor of accusative case and unambiguously dative-marked NPs did not trigger significant ERP differences. We will discuss the implications of our results for parsing and its neuropsychological correlates. The results of this study support a parser design according to which the so-called structural case (nominative or accusative) is assigned without any delay in the absence of morpho-lexical counterevidence. It is argued that the enhancement of a negative ERP component with a "classical" N400 topography reflects the difficulty of reanalysis due to reaccessing morpho-lexical information that lies outside the domain of the parsing module. Consequently, ERP responses to garden-path effects are not confined to a late positivity but vary depending on the level of processing involved in reanalysis. The fact that garden-path effects may also elicit an N400 can be linked to the nonhomogeneous linguistic properties of the constructions from which they arise.

Adult↗
PubMed1983

Comment on Lidz and associates' critique of the Danish-American studies of the offspring of schizophrenic parents.

The author replies to a critique by Lidz and associates of the Greater Copenhagen Adoption Study conducted by Rosenthal and colleagues. A detailed examination of the reanalysis by Lidz and associates of tabulated data from the original adoption study reports substantiates only one of their objections. The author argues that, because of the way in which the original data were gathered, the reanalysis is without substantial merit in evaluating the adoption study.

Adoption↗
PubMed1992

The differential effect of psychotherapy and psychoanalysis with anaclitic and introjective patients: the Menninger Psychotherapy Research Project revisited.

Analyses of the data from the Menninger Psychotherapy Research Project (MPRP) have consistently indicated little difference in the therapeutic outcome between patients seen in psychoanalysis and those seen in psychotherapy. Reanalysis of the data from the MPRP, utilizing a distinction between two broad configurations of psychopathology (Blatt, 1974, 1990a; Blatt and Shichman, 1983), however, indicates that patients whose pathology focuses primarily on disruptions of interpersonal relatedness and who use primarily avoidant defenses (anaclitic patients), and patients whose pathology focuses primarily on issues of self-definition, autonomy, and selfworth and who use primarily counteractive defenses (introjective patients) differ in their responsiveness to psychotherapy and psycho-analysis. Based on recently developed procedures for systematically evaluating the quality of object representation on the Rorschach, reanalysis of the Menninger data reveals that anaclitic patients have significantly greater positive change in psychotherapy, while introjective patients have significantly greater positive change in psychoanalysis. These statistically significant patient-by-treatment interactions are discussed in terms of their clinical implications as well as the importance of differentiating among types of patients in studies of therapeutic outcome and of therapeutic process.

Adult↗
PubMedDate not supplied

Clinical implications of amylin and amylin deficiency.

PURPOSE: This paper presents an overview of the physiology of glycemic control and the mechanisms of amylin deficiency in people with diabetes. Benefits of replacement therapy with both pramlintide and insulin are discussed. METHODS: The discovery of the pancreatic beta-cell hormone amylin, which is cosecreted with insulin in response to hyperglycemia, has prompted a reanalysis of the mechanisms underlying the control of glucose homeostasis. A review of the current literature on amylin and amylin deficiency provides the basis of this reanalysis, with a discussion of the clinical implications for people with diabetes. RESULTS: Amylin appears to work with insulin to regulate plasma glucose concentrations in the bloodstream, suppressing the postprandial secretion of glucagon and restraining the rate of gastric emptying. People with diabetes have a deficiency in the secretion of amylin that parallels the deficiency in insulin secretion, resulting in an excessive inflow of glucose into the bloodstream during the postprandial period. CONCLUSIONS: While insulin replacement therapy is a cornerstone of diabetes treatment, replacement of the function of both amylin and insulin may allow a more complete restoration of the normal physiology of glucose control.

Amyloid↗
PubMed1978

Flow-cytometric analysis of chicken red blood cells.

Flow-cytometric analysis of acriflavin-Feulgen stained chicken erythrocytes shows a complex distribution of amounts of deoxyribonucleic acid fluorescence, the profile consisting of a main peak and a right hand shoulder. This bimodal distribution, an artifact characteristically seen on analysis of flattened cells using orthogonal flow systems, results from fluorescence emission in preferred directions stemming from the combined effects of refractility and orientation of the cells. The shoulder disappears on analysis of lysed erythrocyte ghosts, also on analysis of cells in a medium whose refractive index approximates that the cells. An orientation effect for matrue erythrocytes was indicated by reanalysis of fractions after sorting on the basis of high and low fluorescence or scatter signals. Both fractions gave the original range of values on reanalysis, although some changes in shape of the profile and in the peak positions for the sorted cells were seen. Sodium dodecyl sulfate treatment of stained cells "loosened" the cells' structure, yielding lowered scatter values, and fluorescence values approaching those of the shoulder. The average fluorescence emission of the erythrocytes was lower than that of reticulocytes and lymphocytes. The values of the latter correspond closely, although coincidently, to that the erythrocyte shoulder values. Dual parameter analysis of forward light scatter, and fluorescence, which was detected at 90 degrees to the laser beam, showed the low fluorescence to be accompanied by low scatter signal, and the high fluorescence among the cells with the high scatter signal. The lowered forward scatter signal is due to a wider scattering of light from cells oriented edge-on to the detector, and loss of signal beyond the acceptance angle of the detector. These results suggest that the preferred directions for fluorescence are in the plane of the cells, and the values are dependent on the cells' orientation in the stream. These interpretations were supported by the results of analysis of partially oriented cells. The approaches used and conclusions arrived at are similar to those of Gledhill et al (16), Van Dilla et al (37), in their analysis of fluorescence of flat sperm cells although the affects in the case of the erythrocytes are less extreme.

Animals↗
PubMed2003

Intersection tests for single marker QTL analysis can be more powerful than two marker QTL analysis.

BACKGROUND: It has been reported in the quantitative trait locus (QTL) literature that when testing for QTL location and effect, the statistical power supporting methodologies based on two markers and their estimated genetic map is higher than for the genetic map independent methodologies known as single marker analyses. Close examination of these reports reveals that the two marker approaches are more powerful than single marker analyses only in certain cases. Simulation studies are a commonly used tool to determine the behavior of test statistics under known conditions. We conducted a simulation study to assess the general behavior of an intersection test and a two marker test under a variety of conditions. The study was designed to reveal whether two marker tests are always more powerful than intersection tests, or whether there are cases when an intersection test may outperform the two marker approach.We present a reanalysis of a data set from a QTL study of ovariole number in Drosophila melanogaster. RESULTS: Our simulation study results show that there are situations where the single marker intersection test equals or outperforms the two marker test. The intersection test and the two marker test identify overlapping regions in the reanalysis of the Drosophila melanogaster data. The region identified is consistent with a regression based interval mapping analysis. CONCLUSION: We find that the intersection test is appropriate for analysis of QTL data. This approach has the advantage of simplicity and for certain situations supplies equivalent or more powerful results than a comparable two marker test.

Animals↗
PubMed2000

The question of declining sperm density revisited: an analysis of 101 studies published 1934-1996.

In 1992 Carlsen et al. reported a significant global decline in sperm density between 1938 and 1990 [Evidence for Decreasing Quality of Semen during Last 50 Years. Br Med J 305:609-613 (1992)]. We subsequently published a reanalysis of the studies included by Carlsen et al. [Swan et al. Have Sperm Densities Declined? A Reanalysis of Global Trend Data. Environ Health Perspect 105:1228-1232 (1997)]. In that analysis we found significant declines in sperm density in the United States and Europe/Australia after controlling for abstinence time, age, percent of men with proven fertility, and specimen collection method. The declines in sperm density in the United States (approximately 1.5%/year) and Europe/Australia (approximately 3%/year) were somewhat greater than the average decline reported by Carlsen et al. (approximately 1%/year). However, we found no decline in sperm density in non-Western countries, for which data were very limited. In the current study, we used similar methods to analyze an expanded set of studies. We added 47 English language studies published in 1934-1996 to those we had analyzed previously. The average decline in sperm count was virtually unchanged from that reported previously by Carlsen et al. (slope = -0.94 vs. -0.93). The slopes in the three geographic groupings were also similar to those we reported earlier. In North America, the slope was somewhat less than the slope we had found for the United States (slope = -0.80; 95% confidence interval (CI), -1.37--0.24). Similarly, the decline in Europe (slope = -2.35; CI, -3.66--1.05) was somewhat less than reported previously. As before, studies from other countries showed no trend (slope = -0.21; CI, -2.30-1.88). These results are consistent with those of Carlsen et al. and our previous results, suggesting that the reported trends are not dependent on the particular studies included by Carlsen et al. and that the observed trends previously reported for 1938-1990 are also seen in data from 1934-1996.

Adolescent↗
PubMed1998

An empirical comparison of lead exposure pathway models.

Structural equation modeling is a statistical method for partitioning the variance in a set of interrelated multivariate outcomes into that which is due to direct, indirect, and covariate (exogenous) effects. Despite this model's flexibility to handle different experimental designs, postulation of a causal chain among the endogenous variables and the points of influence of the covariates is required. This has motivated the researchers at the University of Cincinnati Department of Environmental Health to be guided by a theoretical model for movement of lead from distal sources (exterior soil or dust and paint lead) to proximal sources (interior dust lead) and then finally to biologic outcomes (handwipe and blood lead). The question of whether a single structural equation model built from proximity arguments can be applied to diverse populations observed in different communities with varying lead amounts, sources, and bioavailabilities is addressed in this article. This reanalysis involved data from 1855 children less than 72 months of age enrolled in 11 studies performed over approximately 15 years. Data from children residing near former ore-processing sites were included in this reanalysis. A single model adequately fit the data from these 11 studies; however, the model needs to be flexible to include pathways that are not frequently observed. As expected, the more proximal sources of interior dust lead and handwipe lead were the most important predictors of blood lead; soil lead often had a number of indirect influences. A limited number of covariates were also isolated as usually affecting the endogenous lead variables. The blood lead levels surveyed at the ore-processing sites were comparable to and actually somewhat lower than those reported in the the Third National Health and Nutrition Examination Survey. Lessened bioavailability of the lead at certain of these sites is a probable reason for this finding.

Child, Preschool↗
PubMed2002

Lumbar spine bone measurements in infants: whole-body vs lumbar spine dual X-ray absorptiometry scans.

Availability of software delineation of the lumbar spine region from infant whole-body (IWB) dual energy X-ray absorptiometry scan offers an opportunity to gain additional information at the lumbar spine without a separate scan, although the validity of this technique has never been tested. Lumbar spine measurements derived from IWB scans using software-delineated first to fourth lumbar vertebrae, and from specific infant spine (IS) scans, were determined in 111 infants using two pencil-beam densitometers. Intraoperator repeatability determined by reanalysis of 10 pairs of IWB and IS scans from each densitometer. Lumbar spine area, bone mineral content, and bone mineral density from IWB and IS scans were significantly correlated r = 0.68-0.95, p < 0.001 for all comparisons) but show poor agreement (Bland-Altman method) with one SD of the differences equal to 26-55% of the mean. Intraoperator reanalysis shows good agreement with one SD of the differences from IWB scans at <7% of the mean, and <2.9% from IS scans. Findings were the same for both densitometers. We conclude that lumbar spine bone measurements from IWB or IS scans are highly reproducible and significantly correlated but data from IWB scans cannot substitute for data from IS scans.

Absorptiometry, Photon↗
PubMedDate not supplied

Shape optimization of plate with static and dynamic constraints via virtual laminated element.

The virtual laminated element method (VLEM) can resolve structural shape optimization problems with a new method. According to the characteristics of VLEM, only some characterised layer thickness values need be defined as design variables instead of boundary node coordinates or some other parameters determining the system boundary. One of the important features of this method is that it is not necessary to regenerate the FE(finite element) grid during the optimization process so as to avoid optimization failures resulting from some distortion grid elements. The thickness distribution in thin plate optimization problems in other studies before is of stepped shape. However, in this paper, a continuous thickness distribution can be obtained after optimization using VLEM, and is more reasonable. Furthermore, an approximate reanalysis method named "behavior model technique" can be used to reduce the amount of structural reanalysis. Some typical examples are offered to prove the effectiveness and practicality of the proposed method.

Computer Simulation↗
PubMed1998

The protective effect of condoms and nonoxynol-9 against HIV infection.

OBJECTIVES: Whether or not spermicides can reduce the risk of human immunodeficiency virus (HIV) transmission remains an important question for the control of heterosexual HIV transmission. The authors provide estimates from a reanalysis of one of the few observational studies on the efficacy of condoms and spermicides, used separately and together, per vaginal contact. METHODS: In this reanalysis, three different models were used to assess the efficacy of spermicides and condoms: linear (Pearl index), exponential (maximum likelihood), and monotonic (marginal likelihood). RESULTS: Reported use of barrier methods among 27,432 contacts was as follows: condoms plus nonoxynol-9, 39%; condoms alone, 25%; nonoxynol-9 alone, 24%; and unprotected, 11%. Under all three models, the results indicate a strong protective effect for spermicidal suppositories. The Pearl index indicated that spermicide alone is apparently efficacious, but the efficacy per contact cannot be quantified with this approach. Maximum likelihood estimates for the efficacy of nonoxynol-9 alone and condoms (with or without nonoxynol-9) were 100% (95% confidence interval [CI95] = 43%, 100%) and 92% (95% CI95 = 79%, 100%), respectively. CONCLUSIONS: The data from this observational study suggest that spermicides may be efficacious in reducing the risk of HIV transmission.

Administration, Intravaginal↗
PubMed1984

Skull fracture and the low risk of intracranial sequelae in minor head trauma.

The presence of skull fracture has been associated with a higher risk of intracranial sequelae than if a fracture were not present. This is true for the total population of head-injury patients. However, reanalysis of the patient selection criteria data from two large published series on skull imaging in head trauma revealed that this increased risk factor for intracranial sequelae did not apply to a specific subset of minor-head-trauma patients. The patients in this subset were characterized by the presence of one or more of five "low-yield" criteria: (1) asymptomatic (no complaints), (2) headaches, (3) dizziness, (4) scalp hematoma, and (5) scalp laceration. All other criteria were absent. Results of the reanalysis showed (from a total population of 3031 head-trauma patients) a subset of 1184 patients characterized by these five criteria. In these 1184 minor-head-trauma patients there were 19 fractures, all linear, with none depressed or basilar. There were no intracranial sequelae. This change in the concept of fracture as a risk factor for intracranial sequelae has major implications in the future development of strategies for selecting patients for not having skull films or head computed tomograms.

Brain Injuries↗
PubMed1992

Age of acquisition, not word frequency, affects object naming, not object recognition.

Word frequency is widely believed to affect object naming speed, despite several studies in which it has been reported that frequency effects may be redundant upon age of acquisition. We report, first, a reanalysis of data from the study by Oldfield and Wingfield (1965), which is standardly cited as evidence for a word frequency effect in object naming; then we report two new experiments. The reanalysis of Oldfield and Wingfield shows that age of acquisition is the major determinant of naming speed, and that frequency plays no independent role when its correlation with other variables is taken into account. In Experiment 1, age of acquisition and phoneme length proved to be the primary determinants of object naming speed. Frequency, prototypicality, and imageability had no independent effect. In Experiment 2, subjects classified objects into two semantic categories (natural or man-made). Prototypicality and semantic category were the only variables to have a significant effect on reaction time, with no effect of age of acquisition, frequency, imageability, or word length. We conclude that age of acquisition, not word frequency, affects the retrieval and/or execution of object names, not the process of object recognition. The locus of this effect is discussed, along with the possibility that words learned in early childhood may be more resistant to the effects of brain injury in at least some adult aphasics than words learned somewhat later.

Adult↗
PubMed1993

Visual angle as a determinant of perceived interobject distance.

Two new experiments and a reanalysis of Toye's (1986) data are used to examine the relationship between true distance and perceived distance in natural scenes. In the first experiment, 8 subjects estimated 78 interobject distances, formed by all pairs of 13 objects, while viewing the objects from a fixed position. The results showed that estimated distance is a linear function of the visual angle between objects as well as of the true distance. This relationship results in distances perpendicular to the line of sight being overestimated in relation to true distances and to distances parallel to the line of sight. These findings were confirmed by reanalysis of a comparable data set from Toye. Since changes in the visual angle can come about through changes in alignment with the line of sight, viewing distance, or interobject distance, Experiment 2 was designed to determine whether the visual angle effect was due to one of these, or whether it was an independent effect. In Experiment 2, 8 subjects estimated six interobject distances from 12 viewing positions. The results showed that visual angle predicted estimated distance independently of how the change in visual angle came about, suggesting that the greater the visual angle between objects, the more their separation is overestimated.

Adult↗
PubMed2002

Classic or Bayesian research design and analysis. Does it make a difference?

OBJECTIVE: The role of classical and Bayesian statistical approaches remains in dispute in health services research and policy. The goal of this study was to determine if results differ when both analytic techniques are used with the same data set. DESIGN: We searched MEDLINE and related databases for English-language articles published January 1, 1978 through August 31, 1999. We combined Bayesian and classical statistics search terms and their variants with randomized control trials (RCTs) and meta-analyses. RESULTS: Searches found 18 studies in 14 publications that met all review criteria--nine RCTs, eight meta-analyses, and one epidemiologic estimate. Statistical analyses using both methods agreed in five RCTs, four meta-analyses, and for the epidemiologic estimates. For four RCTs where results disagreed, classical analysis found the experimental intervention was efficacious compared with the control, and Bayesian reanalysis concluded the intervention was not proven efficacious. Classical meta-analyses of the four studies where results disagreed concluded the experimental intervention was not better than the control; Bayesian reanalysis concluded it was efficacious. CONCLUSION: Classical and Bayesian methods in this review exhibited important divergence of results. Disagreement on many fundamental beliefs between classical and Bayesian statistics means continuing debate. One way to resolve this debate is for proponents of each technique to decide together the circumstances for use of each method and analytic framework. If the experts do not agree on the methodologic requirements, other decision makers likely will force their own views.

Bayes Theorem↗
PubMed2002

Selenium supplementation and lung cancer incidence: an update of the nutritional prevention of cancer trial.

Interest in the chemopreventive effects of the trace element selenium has spanned the past three decades. Of >100 studies that have investigated the effects of selenium in carcinogen-exposed animals, two-thirds have observed a reduction in tumor incidence and/or preneoplastic endpoints (G. F. Combs and S. B. Combs, The Role of Selenium in Nutrition Chapter 10, pp. 413-462. San Diego, CA: Academic Press, 1986, and B. H. Patterson and O. A. Levander, Cancer Epidemiol. Biomark. Prev., 6: 63-69, 1997). The Nutritional Prevention of Cancer Trial, a randomized clinical trial reported by Clark et al. (L. C. Clark et al., JAMA, 276: 1957-1963, 1996), showed as a secondary end point, a statistically significant decrease in lung cancer incidence with selenium supplementation. The adjusted hazard ratio (HR) was 0.56 [95% confidence interval (CI), 0.31-1.01; P = 0.05]. These results were based on active follow-up of 1312 participants. This reanalysis used an extended Nutritional Prevention of Cancer Trial participant follow-up through the end of the blinded clinical trial on February 1, 1996. The additional 3 years added 8 cases to the selenium-treated group and 4 cases to the placebo group, and increased follow-up to 7.9 years. The relative risk of 0.70 (95% CI, 0.40-1.21; P = 0.18) is not statistically significant. Whereas the overall adjusted HR is not significant (HR = 0.74; 95% CI, 0.44-1.24; P = 0.26), and the HR for current and former smokers was not significant, the trend is toward a reduction in risk of incident lung cancer with selenium supplementation. In a subgroup analysis there was a nominally significant HR among subjects with baseline plasma selenium in the lowest tertile (HR = 0.42; 95% CI, 0.18-0.96; P = 0.04). The analysis for the middle and highest tertiles of baseline showed HRs of 0.91 and 1.25. The current reanalysis indicates that selenium supplementation did not significantly decrease lung cancer incidence in the full population, but a significant decrease among individuals with low baseline selenium concentrations was observed.

Aged↗
PubMed2000

Current status and future plans of Nuclear Medicine Procedure Guidelines in Central and Eastern European EANM member societies compared with those in other EANM member societies.

The main aim of the EANM Task Group on Quality Assurance and Standardisation is to develop harmonised clinical procedures that are accepted within Europe. In order to achieve an evidence-based analysis of guidelines this Task Group conducted a survey by means of a questionnaire in the 27 EANM member societies in July 1999, which investigated the current status of national guidelines in EANM member societies, specification of the cover and level of these national guidelines, and future desires for national, EANM and SNM guidelines. A reanalysis of the data of this survey was undertaken to evaluate the differences and similarities between 9 Central and Eastern European (CEE) EANM member societies and 18 non-CEE (mainly Western European) EANM member societies with regard to the aforementioned investigated topics. The results of this reanalysis show only minor differences between CEE and non-CEE EANM member societies with regard to the aforementioned topics. Both in CEE and in non-CEE EANM member societies, there is limited coverage of existing guidelines, leaving most procedures uncovered. Although the infrastructure for guideline development is present in both groups, the main explanation for this similarity is the limited advancement of the guideline development process, in both the CEE and non-CEE EANM member societies. Both groups are willing and ready for guideline development at the EANM level, with more concordant than discordant reasons for this. This allows a synchronous implementation of procedure guidelines in CEE EANM member societies.

Editorial↗
PubMed2006

Perspectives on the recent decline in disability at older ages.

This brief summarizes a recent study exploring the decline in disability observed among the elderly population in national, longitudinal surveys between 1982 and 1999. The brief outlines survey design features that may contribute to reports of declining disability. In addition, the brief explores social trends, such as reduced availability of informal care, increased use of assistive technologies and changes in respondents' perceptions of "disability" over time that may be important contributors to declining disability. Finally, the brief presents the results of a reanalysis of the National Long Term Care Survey (NLTCS) to evaluate the role of several survey design and social factors on reported declines in disability. Using alternative measures of disability, this reanalysis confirmed that disability declined among the elderly population. However, the study found a more gradual decline in any disability compared to previous analyses of the NLTCS. These results point to the importance of survey design features and societal trends in interpreting recent declines in disability among the elderly.Further, the effects of survey design and societal factors on disability estimates make it difficult to extrapolate current disability trends into the future and to predict costs to Medicare, Medicaid and other public programs that serve the elderly.

Activities of Daily Living↗