Search results for "Singleton"
showing 10 items of 12 documents
Neighbourhood socio-economic characteristics and the risk of preterm birth for migrant and non-migrant women: a study in a French district
2011
Neighbourhood-level deprivation is associated with preterm birth; preterm birth rates are also higher for some, but not all migrant groups. We studied the impact of neighbourhood characteristics (a deprivation score and the proportion of foreign-born residents) on singleton preterm birth in the French district of Seine-Saint-Denis for women born in France, North Africa, sub-Saharan Africa and other countries. Multilevel logistic regression models were adjusted for maternal demographic and health care characteristics. For women born in France, the preterm birth rate rose with neighbourhood deprivation quintile (3.8% in the first to 5.7% in the fifth, adjusted odds ratio: 1.40 [95% confidence…
Should Vanishing Twin Pregnancies Be Systematically Excluded From Cell-Free Fetal DNA Testing?
2020
Objective To demonstrate the feasibility of cell-free DNA (cfDNA) testing in vanishing twin (VT) pregnancies in routine clinical practice. Methods Our study included 24 874 singleton and 206 VT consecutive pregnancies. Cell-free DNA was analyzed by massively parallel sequencing. Both aneuploidy analysis (chromosomes 13,18, 21, X, and Y) and fetal fraction estimation were performed according to an Illumina algorithm. Contaminant DNA contribution from the demised co-twin was studied in detail. Results VT pregnancies exhibited a higher prevalence of screen-positive cases (5.8% vs 2.5%), sex discrepancies (10.2% vs 0.05%), and false positive rates (FPR) (2.6% vs 0.3%) than singleton pregnancies…
Coffee and Smoking as Risk Factors of Twin Pregnancies: The Danish National Birth Cohort
2007
AbstractTwinning rates have changed substantially over time for reasons that are only partly known. In this study we studied smoking, coffee and alcohol intake, and their possible interaction with obesity as potential determinants of twinning rates using data from the Danish National Birth Cohort between 1996 and 2002. We identified 82,985 pregnancies: 81,954 singleton and 1031 twins. For the twins we had data to classify 121 as monozygotic, 189 dizygotic (same sex), 313 dizygotic (opposite sex) but, 408 were of the same sex but with unknown zygosity. All mothers were interviewed about their prepregnancy weight and height, coffee and alcohol intake, smoking habits, and potential confounding…
Countably compact weakly Whyburn spaces
2015
The weak Whyburn property is a generalization of the classical sequential property that was studied by many authors. A space X is weakly Whyburn if for every non-closed set \({A \subset X}\) there is a subset \({B \subset A}\) such that \({\overline{B} \setminus A}\) is a singleton. We prove that every countably compact Urysohn space of cardinality smaller than the continuum is weakly Whyburn and show that, consistently, the Urysohn assumption is essential. We also give conditions for a (countably compact) weakly Whyburn space to be pseudoradial and construct a countably compact weakly Whyburn non-pseudoradial regular space, which solves a question asked by Angelo Bella in private communica…
Exposure to elevated temperatures and risk of preterm birth in Valencia, Spain
2014
Abstract Background Prematurity is the second-leading cause of death in children under the age of 5 worldwide. It is predicted that the future climate will have more intense, longer lasting and frequent extreme heat episodes, and so the temperature effect on the risk of preterm birth is generating considerable interest in the public health field. Our aim was to explore the potential short-term effects of elevated temperatures on the risk of preterm birth in Valencia (Spain). Methods All singleton natural births born in the metropolitan area of Valencia during the warm season (May–September, 2006–2010) were included ( N =20,148). We applied time-series quasi-Poisson generalized additive mode…
Some Properties of Massless Particles in Arbitrary Dimensions
1998
Various properties of two kinds of massless representations of the n-conformal (or (n+1)-De Sitter) group [Formula: see text] are investigated for n≥2. It is found that, for space-time dimensions n≥3, the situation is quite similar to the one of the n=4 case for Sn-massless representations of the n-De Sitter group [Formula: see text]. These representations are the restrictions of the singletons of [Formula: see text]. The main difference is that they are not contained in the tensor product of two UIRs with the same sign of energy when n>4, whereas it is the case for another kind of massless representations. Finally some examples of Gupta–Bleuler triplets are given for arbitrary spin and…
THREE-D SINGLETONS AND 2-D C.F.T.
1992
Two-dimensional Wess-Zumino-Novikov-Witten theory is extended to three dimensions, where it becomes a scalar gauge theory of the singleton type. The three-dimensional formulation involves a scalar field valued in a compact group G, a Nakanishi-Lautrup field valued in Lie (G) and Faddeev-Popov ghosts. The physical sector, characterized by the vanishing of the Nakanishi-Lautrup field, coincides with the WZNW theory of the group G. Three-dimensional space-time structure involves a generalized metric, but only its boundary values are of consequence. An alternative formulation in terms of left and right movers (in three dimensions!) is also possible.
Approximate solutions for two-level optimization problems
1988
This paper is devoted to general results for approximating two-level optimization problems in which the set of solutions to the lower level problem is not a singleton.
Analysis of Caesarean Section Rates Using the Robson Classification System at a University Hospital in Spain
2020
Background: The WHO recommends the use of the Robson ten-group classification system (RTGCS) as an effective monitoring and analysis tool to assess the use of caesarean sections (CS). The present study aimed to conduct an analysis of births using the RTGCS in La Ribera University Hospital over nine years and to assess the levels and trends of CS births. Methods: Retrospective study between January 1, 2010, and December 31, 2018. All eligible women were allocated in RTGCS to determine the absolute and relative contribution made by each group to the overall CS rate
Long-term prediction of birth weight
1993
On the basis of the hypothesis that undisturbed individual growth in fetal life keeps a constant proportional difference with the standard population 50th percentile, birth weight can be predicted with a single sonographic exploration after the 16th week of pregnancy. Data on 135 singleton pregnancies with accurate dates and delivery at term were used. Sonography was performed between the 17th and 36th weeks of pregnancy, in every case at least 4 weeks before delivery. The observed measurements of BPD, FL, and AC were used for the prediction of their values on the day of delivery, applying the Hadlock equation for the estimation of birth weight. The mean error of birth weight predictions wa…