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Results for “Generation mean analysis”

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PubMed1989

[Variations in expressivity and penetrance of hypodontia].

The intensity of expressivity and penetrance of anomalies through generations can be established by means of genealogical analysis. In the present study thirty five family pedigrees, including three generation family members, have been analysed. Variable expressivity of hypodontia has been established in 48.57% families. Pedigrees of 21 families showed the autosomal dominant mode of inheritance. Three families expressed hypodontia only in one (third) generation. In 12 families hypodontia has been established only in the proband what was compatible with the polygenic inheritance. In 12 (34.28%) families hypodontia showed penetrance through two generations, and in 9 (25.71%) families penetrance has been observed through three generations.

Anodontia↗

PubMed1997

[Fully automated generation of hip prosthesis voxel models of the femur for finite element analysis. Comparison of direct and subsequent prosthesis implantation].

Two means of generating implant-bearing FE voxel models of the human femur are described and compared. The first method consists in the fully automatic production of a femur model from CT data and subsequent implantation of a prosthesis stem on the basis of a redefinition of existing voxel elements using geometrical data control. The second method processes the CT data of a femur already bearing a prosthesis. Here, the prosthesis elements are generated separately from the surrounding bony elements on the basis of the differing CT density thresholds. Although the two implantation algorithms produce comparable results, they have different fields of application. The method of numerical stress analysis involving automatic generation of voxel models can be applied to implant-bearing femurs. Clinical follow-up observations of patients with prostheses made of titanium can be supported by FE calculations.

Algorithms↗

PubMed2006

Shape statistics variational approach for the outer contour segmentation of left ventricle MR images.

Segmentation of left ventricles is one of the important research topics in cardiac magnetic resonance (MR) imaging. The segmentation precision influences the authenticity of ventricular motion reconstruction. In left ventricle MR images, the weak and broken boundary increases the difficulty of segmenting the outer contour precisely. In this paper, we present an improved shape statistics variational approach for the outer contour segmentation of left ventricle MR images. We use the Mumford-Shah model in an object feature space and incorporate the shape statistics and an edge image to the variational framework. The introduction of shape statistics can improve the segmentation with broken boundaries. The edge image can enhance the weak boundary and thus improve the segmentation precision. The generation of the object feature image, which has homogenous "intensities" in the left ventricle, facilitates the application of the Mumford-Shah model. A comparison of mean absolute distance analysis between different contours generated with our algorithm and that generated by hand demonstrated that our method can achieve a higher segmentation precision and a better stability than various approaches. It is a semiautomatic way for the segmentation of the outer contour of the left ventricle in clinical applications.

Algorithms↗

PubMed2003

Widespread cytoplasmic mRNA transport in yeast: identification of 22 bud-localized transcripts using DNA microarray analysis.

Cytoplasmic mRNA localization provides a means of generating cell asymmetry and segregating protein activity. Previous studies have identified two mRNAs that localize to the bud tips of the yeast Saccharomyces cerevisiae. To identify additional localized mRNAs, we immunoprecipitated the RNA transport components She2p, She3p, and Myo4p and performed DNA microarray analysis of their associated RNAs. A secondary screen, using a GFP-tagged RNA reporter assay, identified 22 mRNAs that are localized to bud tips. These messages encode a wide variety of proteins, including several involved in stress responses and cell wall maintenance. Many of these proteins are asymmetrically localized to buds. However, asymmetric localization also occurs in the absence of RNA transport, suggesting the existence of redundant protein localization mechanisms. In contrast to findings in metazoans, the untranslated regions are dispensable for mRNA localization in yeast. This study reveals an unanticipated widespread use of RNA transport in budding yeast.

Biological Transport↗

PubMed1989

Interference of automated electroencephalographic processing by an endocardial pacemaker.

This article reports a patient with an endocardial pacemaker undergoing a carotid endarterectomy in whom cerebral function was monitored by using processed electroencephalography (EEG). The EEG was processed by means of aperiodic analysis. The pacemaker generated an artifact that was identified on the processed EEG display and on the raw EEG display. During the time of carotid cross-clamping, a loss of EEG activity was noted on careful examination of the processed EEG and confirmed by referring to the raw EEG. Nevertheless, because of the presence of the artifact, the activity edge remained essentially constant despite the change in underlying EEG activity. The cross-clamp was released based on the observed change in EEG activity, yielding a return to baseline EEG activity. The surgeon elected to shunt the patient. The patient awoke without neurologic sequelae. This case serves to demonstrate the importance of referring to the raw EEG signal and the limitations of the activity edge in the presence of artifact.

Carotid Artery Diseases↗

PubMed2000

Herbicide spray drift odor: measurement and toxicological significance.

The toxicological significance of exposure of members of the public to spray drift odors of four herbicide formulations (three 2, 4-dichlorophenoxyacetic [2,4-D] acid derivatives and one MCPA [4-methyl-2-chlorophenoxyacetic acid] derivative) has been studied using a combination of novel odor measurement and classic residue analysis techniques. The mean odor concentrations, generated during the spraying of the commercial herbicide formulations under simulated aerial application conditions, were about twofold higher for 2,4-D ethylhexyl ester (22,500 OU(c)/m(3)) and MCPA (30,100 OU(c)/m(3)) than for 2,4-D butyl ester (12,400 OU(c)/m(3)) and 2,4-D amine (11,800 OU(c)/m(3)). Detailed investigations determined that the odors are due to trace manufacturing impurities and additives in the commercial formulations, whereas the herbicide active ingredients are odorless. Measured airborne herbicide active ingredient concentrations under the simulated aerial application conditions were all below their respective occupational safety and health TLV-TWA values, indicating that exposures of toxicological significance as a result of spray drift are unlikely.

Environmental Exposure↗

PubMed1991

X-ray induced translocations in premeiotic germ cells of monkeys.

The induction of reciprocal translocations by various X-ray exposures was studied in spermatogonial stem cells of rhesus monkeys (Macaca mulatta) and stump-tailed macaques (Macaca arctoides) by means of spermatocyte analysis many cell generations after irradiation. The yields of translocations recovered from irradiated stump-tailed macaques were lower than those observed in rhesus monkeys and represent in fact the lowest induction rates per Gy ever recorded for experimental mammals. In the rhesus monkey a humped dose-effect relationship was found with (a) a homogeneous response with (pseudo-)linear kinetics below 1 Gy, (b) much more variability at higher doses, and (c) no induction at all at doses of 4 Gy and above. It is suggested that the post-irradiation proliferation differentiation pattern of surviving rhesus monkey spermatogonial stem cells i mainly responsible for these characteristics of the dose-response curve.

Animals↗

PubMed1987

The reliability of dietary history from the distant past.

A major barrier to the conduct and interpretation of retrospective studies of diet and cancer has been uncertainty about the reliability of retrospective measures of diet from the distant past. The authors therefore conducted a study to assess the reliability of retrospective dietary reports and to determine whether the retrospective report or the report of current diet is the better indicator of past diet. Persons (n = 323) originally interviewed regarding their diets in 1975-1979 were retrospectively reinterviewed in 1984-1985. There was little difference between the retrospective reports and the reports of current diet when group means were examined as indicators of past diet. The retrospective reports tended to overestimate the past frequency of consumption for most foods, whereas the reports of current diet tended to yield underestimates. Because food frequency-based dietary history data are more useful for ranking study subjects than for generating estimates of group means, correlation analysis was used as the principal assessment of the reliability of the two indicators of past diet. The retrospective reports more closely correlated with the diet reported at the original interview than did the report of current diet (for 37 of 47 foods). Nutrient indices based on the retrospective history were also more highly correlated with those of the original diet than were indices based on the current diet. No differences were noted in the reliability of retrospective reports according to age or sex. Subjects accurately reported perceptions of changes in their consumption of most foods, yet an estimate of past diet created by adjusting current diet for perceived change did not correlate more highly with the original diet than did the retrospective report. The authors conclude that assessing current diet to make inference about diet from the distant past does not yield more reliable estimates of past diet than does the retrospective dietary history. The best estimate of diet from several years in the past may be derived directly from a retrospective dietary history which focuses on that past period of time.

Aged↗

PubMed2002

Conjoint analysis of a new Chemotherapy: willingness to pay and preference for the features of raltitrexed versus standard therapy in advanced Colorectal Cancer.

OBJECTIVE: To estimate the willingness to pay for a new chemotherapy, raltitrexed (Tomudex trade mark ) over conventional therapy with fluorouracil plus leucovorin (FU-LV) from the perspective of patients with advanced colorectal cancer. The study was part of the product's reimbursement application in Australia. DESIGN AND METHODS: The key differences relevant to patients between the two therapies, frequency of administration and severity of mouth ulceration, were used to develop a self-administered questionnaire. A relatively new technique to healthcare, that of conjoint analysis (CA), was used to estimate willingness to pay and strength of preference. A discrete choice CA was used. Analysis was via a logit model with adjustment for the cluster effect (or intra-patient correlation). STUDY PARTICIPANTS: Oncology nurses served as proxies for patients with advanced colorectal cancer. RESULTS: The participation rate was 87% (62/71) with questionnaires from 56 respondents eligible for analysis. The CA method generated a mean incremental willingness to pay of 745 Australian dollars (dollar A; dollars US 507) per cycle of chemotherapy, comprising dollars A 550 (dollars US 374) and dollars A 195 (dollars US 133) for the toxicity and administration improvements, respectively (1998 values). Both features were related to preference with independent odds of 6.87 and 1.98, respectively, however only the toxicity attribute was a significantly related to preference. Subscription to private health insurance was the only significant demographic predictor identified, however, the homogeneous income structure of the respondents seems likely to have masked any significant income effect. CONCLUSIONS: This study highlights the advantages of using CA in healthcare, where new therapies or treatments are often composed of a number of attributes. The CA allows both strength of preference and willingness to pay for individual treatment attributes to be estimated and can be used to assign statistical significance to these parameters.

Adult↗

PubMed2003

The uncertain journey: women's experiences following a myocardial infarction.

Current literature indicates that women, and society in general, do not see coronary heart disease (CHD) as a serious concern for women. This lack of recognition seems, in part, to be related to a lack of research involving women as participants and in developing nursing knowledge specific to women and CHD. Although existing literature provides valuable insight into cardiac recovery, it does not clearly explore women's perceptions of their experiences in the early home convalescent recovery process following a myocardial infarction (MI). This study reports on the supportive-educative experiences of eight English speaking women, ages 33-61, in their early recovery process following an MI. Inductively generated data analysis has provided a means to understand the process of recovery from the perspective of these participants. Inherent in the participants' words, as they discussed their journeys with recovery, was an overwhelming sense of uncertainty while living with heart disease. For these women, their socially constructed knowledge dictated that women, and in particular, young women, did not experience heart attacks, and was, therefore, in conflict with their realities. The contradiction between the 'truths learned from others' and their MI experiences influenced, and was influenced by, the subsequent emerging themes of a 'rude awakening,' 'disconnected knowing,' and 'reconnecting self.' Feminist research challenges tradition and offers nursing an opportunity to explore and investigate issues of importance to our profession in a different way. Nurses, as well as other health care professionals, need to be aware of the social construction of cardiac illness and women's experiences, as this knowledge has great implications for patient care from prevention to rehabilitation within the cardiac experience. Based on the results of this study, implications for nursing education, research and practice are discussed.

Adaptation, Psychological↗

PubMed2000

Inhibition of interleukin-1beta (IL-1beta) production in human cells by ribozymes against IL-1beta and IL-1beta converting enzyme (ICE).

We and others have shown previously that hairpin ribozyme genes, when stably expressed in cells, can reduce the steady-state levels of target mRNA and their cognate proteins. Despite this capability, ribozymes have not been as widely used in knockdown experiments as one might expect, probably because specific rules governing the selection of ribozymes that will have high activity have not been described. In this report, we show that parallel screening of less than 10 ribozyme expression constructs, with no advanced knowledge of cleavage activity or preselection, can efficiently identify knockdown ribozymes. This empirical selection study, which used interleukin-1beta (IL-1beta) and IL-1beta converting enzyme (ICE) as example targets, resulted in (1) the rapid identification of ribozymes that can reduce the production of IL-1beta in THP-1 cultures by 10-fold and (2) the consequent direct generation of stable knockdown cell lines. We conclude, based on these and similar studies, that parallel screening of ribozyme constructs could be used in high throughput gene functional analysis programs as a means of rapidly generating specific knockdown cell lines.

Caspase 1↗

PubMed1995

The meaning of work for older adults seeking employment: the generativity factor.

This study is a theory-based examination of the meaning of work for older adults in a sample of 146 older job-seekers. It proposes four factors to the meaning of work: Financial, Personal, Social, and the Generativity factor. The Generativity factor, unique to older adults, refers to viewing work as a way to teach, train and share skills with younger generations. A factor analysis of a 16-item Meaning of Work Scale (MWS) supports the proposed four factors. The results indicate ethnic and employment differences with respect to the meaning of work, but no gender differences. Significant differences were detected between older adult job-seekers who obtained a job within a year of job search and those who did not, with respect to the personal factor of the MWS and with respect to ethnicity. The findings indicate that jobs providing opportunities for transfer of knowledge and experience to younger generations may be of particular value for older adults.

Aged↗

PubMed1999

Latent class analysis applied to patterns of fetal sonographic abnormalities: definition of phenotypes associated with aneuploidy.

The aim of the present study was to generate different latent variables that classify the major chromosome aneuploidies using frequency and patterns of fetal sonographic abnormalities in a large database. A total of 1867 fetuses with sonographic abnormalities recorded in a database at New England Medical Center from January 1995 to March 1998 were available for the statistical analysis. Included within this group were 61 aneuploid fetuses, including 11 with 45,X, 30 with trisomy 21, 14 with trisomy 18 and 6 with trisomy 13, 40 structural malformations and/or sonographic markers were detected in these 61 aneuploid fetuses. The ability of malformations and sonographic markers to generate different groups of phenotypes was evaluated by means of latent class analysis, using the 61 affected cases. Four different classes were generated with the hypothetical assumption that each of them could satisfactorily identify a respective fetal aneuploidy represented in the study group. Among 40 fetal malformations and/or sonographic markers, the most important findings in generating specific karyotypic groups were cystic hygroma (class 1), duodenal atresia (class 2), holoprosencephaly (class 3) and omphalocele (class 4), respectively. Accuracy of the classification was 72 per cent for Turner syndrome (class 1), 74 per cent for Down syndrome (classes 1 and 2), 88 per cent for trisomy 13 (class 3) and 93 per cent for trisomy 18. The frequency of associated malformations detected sonographically can help to define a phenotype that is likely to be representative of a specific aneuploidy. Before the definitive karyotype is available or, in cases in which patients refuse an invasive prenatal diagnostic procedure, this may improve antenatal clinical management.

Aneuploidy↗

PubMed2003

Circularly polarized beams and vortex generation in uniaxial media.

We deduce the expressions for the two circularly polarized components of a paraxial beam propagating along the optical axis of a uniaxial crystal. We find that each of them is the sum of two contributions, the first being a free field and the second describing the interaction with the opposite component. Moreover, we expand both components as a superposition of vortices of any order, thus obtaining a complete physical picture of the interaction dynamics. Consequently, we argue that a left-hand circularly polarized incoming beam, endowed with a circular symmetric profile, gives rise, inside the crystal, to a right-hand circularly polarized vortex of order 2. The efficiency of this vortex generation is investigated by means of a power exchange analysis. The Gaussian case is fully discussed, showing the relevant features of the vortex generation.

Journal Article↗

PubMed1982

[Simultaneous determination of zymogen activation time and zymogen level using chromogenic substrates in blood coagulation analysis].

The amidolytic activities of plasma generated by means of thromboplastin and Ca++, on the one hand, and by means of partial thromboplastin, a contact activator and Ca++, on the other hand, were determined using synthetic, chromogenic factor Xa substrates with low affinity for thrombin (CH3SO2-D-Leu-Gly-Arg-pNA and CH3SO2-D-Nleu-Gly-Arg-pNA). In this way, the activation process by splitting off the p-nitroaniline was followed. Besides the summary detection of factor Xa was obtained after addition of hirudin. During preincubation with partial thromboplastin and contact acti (Actin) in Ca++-free medium, an amidolytic activity so far unidentified was generated that renders evaluation of the activation process difficult. In the test system with partial thromboplastin, factor Xa could not be determined and the thrombin-like activity that can be inhibited by hirudin did not correspond to the amount of prothrombin present in plasma. In contrast, activation of factor X and prothrombin by thromboplastin and Ca++ could be followed and the content of the two zymogenes could be detected simultaneously. In general, under optimized reaction conditions, automated systems might be developed that would provide additional diagnostic information about determination of clotting time, on the one hand, and about quantitative determination of zymogen, on the other hand.

Calcium↗

PubMed2004

The meaning of health: perspectives of Anglo and Latino older women.

This qualitative study, utilizing the dimensional analysis approach, was conducted to generate a substantive theory about the description and meaning of functional health from the perspectives of older Anglo and Latino women. Through focus group interviews with older Anglo and Latino women and data analysis, the investigators learned that the women's perceptions of functional health were vastly different. As planners and providers, we usually are trained in a health culture that is predominantly based on White, middle-class values. This ethnocentrism can act as a barrier leading us to disregard the notion that concepts such as health are not universally perceived. Findings from this study may enable us to achieve a closer approximation of the real experiences of our clients and to sensitize us to different world views.

Aged↗

PubMed2002

Insulin-like growth factor I (IGF-I) and IGF-binding protein 3 response to growth hormone is impaired in HIV-infected children.

To better characterize the somatotropic axis in HIV-infected children the circadian rhythm of growth hormone (GH), and basal and stimulated (by an insulin-like growth factor I [IGF-I] generation test) plasma levels of IGF-I and insulin-like growth factor-binding protein 3 (IGFBP-3), were evaluated in 16 children (9 boys and 7 girls; age range, 7-11 years) with HIV infection. All patients were free from active opportunistic infection or liver disease at the time of the study. Sixteen age- and sex-matched healthy children (10 boys and 6 girls; age range, 7-11 years) served as control subjects. GH rhythmometric data were analyzed by single and population mean cosinor analysis. As regards the IGF-I generation test, biosynthetic human GH (hGH, 0.1 IU/kg, 0.033 mg/kg) was administered subcutaneously for 4 days and blood samples were taken from fasting subjects at baseline and on the morning after the last GH injection for measurement of IGF-I and IGFBP-3. Plasma GH levels fell within normal limits in the HIV-seropositive patients and were similar to those of healthy children (1.31 +/- 1.18 vs. 1.57 +/- 1.16 microg/liter, respectively; mean +/- SD). The population mean cosinor analysis shows that the GH circadian rhythm reached statistical significance both in the HIV-seropositive children and in the control group. Despite this, the IGF-I and IGFBP-3 levels were significantly lower in HIV-infected children than in the control group (75.6 +/- 57.2 vs. 233.3 +/- 52.5 ng/ml, p < 0.001 and 2.09 +/- 0.17 vs. 3.89 +/- 0.24 mg/liter, p < 0.01, respectively; mean +/- SD); moreover, the response of IGF-I and IGFBP-3 to the IGF-I generation test was significantly lower in HIV-infected children than in the control group (86.3 +/- 55.8 vs. 257.5 +/- 53.4 ng/ml, p < 0.001 and 3.14 +/- 0.43 mg/liter, p < 0.01, respectively; mean +/- SD). It appears that circadian GH secretion is normal in children with HIV infection, but the response to exogenous GH with regard to IGF-I and IGFBP-3 production is impaired, indicating a degree of GH insensitivity in such children.

Child↗

PubMed1987

Methodology for detection of heterogeneity of cell locomotory phenotypes in three-dimensional gels.

A computer-driven, three-dimensional, optical, cell-tracking system was used to quantify the locomotory phenotypes of Mos-11 cells in a collagen gel. Factor analysis was used as a statistical means to make the complex variables generated by the system more tractable to analysis. Heterogeneity in locomotory behavior (two independent locomotory phenotypes) was detected among a sample of 54 cells.

Cell Line↗