177,243 research outputs found
Prospective first-trimester screening for trisomies by cell-free DNA testing of maternal blood in twin pregnancy
No full textFirst, to examine in twin pregnancies the performance of first-trimester screening for fetal trisomies 21, 18 and 13 by cell-free (cf) DNA testing of maternal blood and, second, to compare twin and singleton pregnancies regarding the distribution of fetal fraction of cfDNA and rate of failure to obtain a result
Screening for trisomies by cell-free DNA testing of maternal blood: consequences of a failed result
No full textFirst, to report the distribution of the fetal fraction of cell-free (cf) DNA and the rate of a failed cfDNA test result in trisomies 21, 18 and 13, by comparison with pregnancies unaffected by these trisomies, second, to examine the possible effects of maternal and fetal characteristics on the fetal fraction, and third, to consider the options for further management of pregnancies with a failed result
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Early prediction of preeclampsia
No full textPreeclampsia (PE) is a major cause of perinatal and maternal morbidity and mortality.
In the United Kingdom, the National Institute for Clinical Excellence (NICE) has
issued guidelines on routine antenatal care recommending that at the booking visit a
woman’s level of risk for PE should be determined and the subsequent intensity of
antenatal care should be based on this risk assessment. This method relies on a risk
scoring system derived from maternal characteristics and medical history; the
performance of screening by this method is poor with detection of less than 50% of
cases of preterm-PE and term-PE.
The objective of this thesis is to develop a method for the estimation of the patient-specific
risk for PE by combining the a priori risk based on maternal characteristics
and medical history with the results of biophysical and biochemical markers obtained
at 11-13 weeks’ gestation. Such early identification of high-risk pregnancies could
lead to the use of pharmacological interventions, such as low-dose aspirin, which could
prevent the development of the disease.
The data for the thesis were derived from two types of studies: First, prospective
screening in 65,771 singleton pregnancies, which provided data for maternal factors
and serum pregnancy associated plasma protein-A (PAPP-A). In an unselected
sequential process we also measured uterine artery pulsatility index (PI) in 45,885 of
these pregnancies, mean arterial pressure (MAP) in 35,215 cases and placental growth
factor (PLGF) in 14,252 cases. Second, cases-control studies for evaluating the ten
most promising biochemical markers identified from search of the literature; for these
studies we used stored serum or plasma samples obtained during screening and
measured PLGF, Activin-A, Inhibin-A, placental protein-13 (PP13), P-selectin,
Pentraxin-3 (PTX-3), soluble Endoglin (sEng), Plasminogen activator inhibitor-2
(PAI-2), Angiopoietin-2 (Ang-2) and soluble fms-like tyrosine kinase-1 (s-Flt-1). A competing risk model was developed which is based on Bayes theorem and
combines the prior risk from maternal factors with the distribution of biomarkers to
derive patient-specific risk for PE at different stages in pregnancy. The prior risk was
derived by multiple regression analysis of maternal factors in the screening study. The
distribution of biophysical and biochemical markers was derived from both the
screening study and the case-control studies.
The prior risk increased with advancing maternal age, increasing weight, was higher
in women of Afro-Caribbean and South-Asian racial origin, those with a previous
pregnancy with PE, conception by in vitro fertilization and medical history of chronic
hypertension, type 1 diabetes mellitus and systemic lupus erythematosus (SLE) or antiphospholipid
syndrome (APS). The estimated detection rate (DR) of PE requiring
delivery at <34, <37 weeks’ gestation and all PE, at false positive rate (FPR) of 10%,
in screening by maternal factors were 51, 43 and 40%, respectively. The addition of
biochemical markers to maternal factors, including maternal serum PLGF and PAPPA,
improved the performance of screening with respective DRs of 74, 56 and 41%.
Similarly, addition of biophysical markers to maternal factors, including uterine artery
PI and MAP, improved the performance of screening with respective DRs of 90, 72
and 57%. The combination of maternal factors with all the above biophysical and
biochemical markers improved the respective DRs to 96, 77 and 54%.
The findings of these studies demonstrate that a combination of maternal factors,
biophysical and biochemical markers can effectively identify women at high-risk of
developing PE
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Association between reduced fetal movements at term and abnormal uterine artery Doppler indices
No full textObjectives To evaluate the association between second-trimester uterine artery (UtA) Doppler pulsatility index (PI) with reduced fetal movements (RFM) and adverse pregnancy outcome at term. Methods This was a retrospective cohort study of all singleton pregnancies referred for routine antenatal care at a fetal medicine unit over a 5-year period. UtA Doppler indices were obtained at the time of the routine anomaly scan between 19 and 23 weeks' gestation to assess the risk for pre-eclampsia. All episodes of RFM within 1 month of the expected date of delivery were recorded. Regression and sensitivity analyses were used to assess the relationship between UtA-PI with RFM, small-for-gestational-age (SGA) fetuses and stillbirth after 36 weeks' gestation. Results Overall, 17 649 pregnancies were included in the analysis, of which 742 presented with RFM, 1494 gave birth to an SGA newborn and 53 were complicated by stillbirth after 36 weeks' gestation. Logistic regression analysis showed a significant and independent association between UtA-PI and RFM (odds ratio (OR), 5.03 (95% CI, 4.21-6.01); P < 0.001), SGA (OR 2.41 (95% CI, 2.09-2.79); P < 0.001) and stillbirth (OR 1.55 (95% CI, 1.21-1.98); P< 0.001). The association between UtA-PI and SGA was significantly stronger in women presenting with RFM than in the rest of the cohort (P < 0.001). Similarly the association between UtA-PI and RFM was significantly stronger in those pregnancies complicated by stillbirth (P < 0.001). Conclusions Compared with normal pregnancies, those complicated by RFM, SGA and stillbirth at term had higher UtA-PI at 19-23 weeks' gestation. These findings support the assertion that RFM at term is independently related to placental dysfunction and subsequent risk for SGA and stillbirth. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd
Letter from R. R. Zellick, Assistant Trust Officer, Anglo California National Bank of San Francisco, to Joseph R. Goodman, October 2, 1942
No full textLetter from R. R. Zellick, Assistant Trust Officer at The Anglo California National Bank of San Francisco, to Joseph R. Goodman, regarding property owned by Dave Tatsuno. Zellick mentions a dispute between current tenants and Tatsuno, and that Tatsuno has asked Goodman to help locate trustworthy tenants.Personal correspondence, organizational records, government documents, publications, and other papers created or collected by Joseph R. Goodman documenting the forced removal and incarceration of Japanese Americans during World War II, as well as organized resistance to incarceration. Included in the collection are records of the Japanese Young Men's Christian Association and the Japanese American Citizens' League in San Francisco, including papers of the Japanese YMCA's executive secretary Lincoln Kanai; Sakai family papers; Goodman's correspondence to and from Japanese American incarcerees, organizations opposing forced removal and incarceration of Japanese Americans, the War Relocation Authority, and others; publications, photographs, and ephemera from the Topaz Relocation Center, where Goodman taught high school; War Relocation Authority records and publications; and newspaper clippings, pamphlets, and reports about forced removal and incarceration created by various government, religious, and civic organizations, in California and nationwide
Fetal middle cerebral artery and umbilical artery pulsatility index: effects of maternal characteristics and medical history
No full textTo define the contribution of maternal variables which influence the measured fetal middle cerebral artery (MCA) and umbilical artery (UA) pulsatility index (PI) in the assessment of fetal wellbeing
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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